diff --git a/src/api/planet/space/space.tsx b/src/api/planet/space/space.tsx
index be14117d..1057331e 100644
--- a/src/api/planet/space/space.tsx
+++ b/src/api/planet/space/space.tsx
@@ -1,4 +1,4 @@
-import { authClient } from "@/api/client";
+import { authClient } from '@/api/client';
 
 // 메인 스페이스 아이디 조회
 export const getMainId = async () => {
@@ -7,6 +7,13 @@ export const getMainId = async () => {
   return response;
 };
 
+// 메인 스페이스 변경
+export const putMainSpace = async (spaceId: string) => {
+  const response = await authClient.put(`/api/v1/spaces/${spaceId}/main`);
+
+  return response;
+};
+
 // 특정 스페이스 조회
 export const getSpaceInfo = async (spaceId: string) => {
   const response = await authClient.get(`/api/v1/spaces/${spaceId}`);
@@ -21,14 +28,14 @@ export const getSpaceList = async () => {
 // 스페이스 생성
 export const postNewSpace = async ({
   spaceName,
-  templateType,
+  templateType
 }: {
   spaceName: string;
   templateType: number;
 }) => {
   return await authClient.post(`/api/v1/spaces`, {
     spaceName: spaceName,
-    templateType: templateType,
+    templateType: templateType
   });
 };
 
@@ -40,30 +47,30 @@ export const deleteSpace = async ({ spaceId }: { spaceId: string }) => {
 // 여러 스페이스 삭제
 export const deleteSpaces = async ({ spaceIds }: { spaceIds: string[] }) => {
   return await authClient.delete(`/api/v1/spaces`, {
-    data: { spaceIds },
+    data: { spaceIds }
   });
 };
 
 // 스페이스 이름 수정
 export const putSpace = async ({
   spaceId,
-  spaceName,
+  spaceName
 }: {
   spaceId: string;
   spaceName: string;
 }) => {
   return await authClient.put(`/api/v1/spaces/${spaceId}/name`, {
-    spaceName,
+    spaceName
   });
 };
 
 // 스페이스 순서 변경
 export const putSpacesOrder = async ({
-  orders,
+  orders
 }: {
   orders: { spaceId: string; index: number }[];
 }) => {
   return await authClient.put(`/api/v1/spaces/order`, {
-    orders,
+    orders
   });
 };
diff --git a/src/app/mypage/send/page.tsx b/src/app/mypage/send/page.tsx
index 66a8d7da..a3ad98d9 100644
--- a/src/app/mypage/send/page.tsx
+++ b/src/app/mypage/send/page.tsx
@@ -1,20 +1,20 @@
-"use client";
+'use client';
 
 import {
   deleteSentLetter,
   deleteSentLetters,
-  getSentLetter,
-} from "@/api/mypage/user";
-import Button from "@/components/common/Button";
-import ConfirmModal from "@/components/common/ConfirmModal";
-import Loader, { LoaderContainer } from "@/components/common/Loader";
-import NavigatorBar from "@/components/common/NavigatorBar";
-import LetterTag from "@/components/mypage/LetterTag";
-import { useToast } from "@/hooks/useToast";
-import { SentLetterListType } from "@/types/letter";
-import { useRouter } from "next/navigation";
-import { Suspense, useEffect, useState } from "react";
-import styled from "styled-components";
+  getSentLetter
+} from '@/api/mypage/user';
+import Button from '@/components/common/Button';
+import ConfirmModal from '@/components/common/ConfirmModal';
+import Loader, { LoaderContainer } from '@/components/common/Loader';
+import NavigatorBar from '@/components/common/NavigatorBar';
+import LetterTag from '@/components/mypage/LetterTag';
+import { useToast } from '@/hooks/useToast';
+import { SentLetterListType } from '@/types/letter';
+import { useRouter } from 'next/navigation';
+import { Suspense, useEffect, useState } from 'react';
+import styled from 'styled-components';
 
 const SendedLetter = () => {
   const [isSelecting, setIsSelecting] = useState(false); // 항목을 선택중인지
@@ -49,7 +49,7 @@ const SendedLetter = () => {
       await fetchDeleteLetter(selectedId);
       setIsSelecting(false);
       setSelectedId([]);
-      console.log("Deleted IDs:", selectedId);
+      console.log('Deleted IDs:', selectedId);
       fetchLetterList();
     }
   };
@@ -69,7 +69,7 @@ const SendedLetter = () => {
   const fetchLetterList = async () => {
     try {
       const response = await getSentLetter();
-      setSenderArray(response.data.content);
+      setSenderArray(response.data.content.reverse());
     } catch (error) {
       console.log(error);
     }
@@ -78,22 +78,22 @@ const SendedLetter = () => {
   const fetchDeleteLetter = async (letterIds: string[]) => {
     if (letterIds.length === 1) {
       try {
-        const response = await deleteSentLetter(letterIds[0]);
+        await deleteSentLetter(letterIds[0]);
         showToast(`1개의 편지가 삭제되었어요`, {
           icon: false,
           close: true,
-          bottom: "50px",
+          bottom: '50px'
         });
       } catch (error) {
         console.log(error);
       }
     } else if (letterIds.length > 1) {
       try {
-        const response = await deleteSentLetters(letterIds);
+        await deleteSentLetters(letterIds);
         showToast(`${letterIds.length}개의 편지가 삭제되었어요`, {
           icon: false,
           close: true,
-          bottom: "50px",
+          bottom: '50px'
         });
       } catch (error) {
         console.log(error);
@@ -105,7 +105,7 @@ const SendedLetter = () => {
     <Container $isSelecting={isSelecting}>
       {isPopup && (
         <ConfirmModal
-          title={selectedId.length + "개의 편지를 정말 삭제할까요?"}
+          title={selectedId.length + '개의 편지를 정말 삭제할까요?'}
           sub="삭제된 편지는 복구되지 않아요."
           onConfirm={discardItems}
           onCancel={cancelItems}
@@ -118,7 +118,7 @@ const SendedLetter = () => {
         <Header>
           {!isSelecting ? (
             <>
-              {" "}
+              {' '}
               <SelectText onClick={() => setIsSelecting(!isSelecting)}>
                 삭제
               </SelectText>
@@ -191,10 +191,10 @@ const Container = styled.div<{
   max-height: 100%;
   justify-content: space-between;
   /* ${({ $isSelecting }) =>
-    $isSelecting ? "justify-content: space-between" : ""}; */
+    $isSelecting ? 'justify-content: space-between' : ''}; */
   color: white;
   background: ${(props) => props.theme.colors.bg};
-  background-image: url("/assets/mypage/img_background.png");
+  background-image: url('/assets/mypage/img_background.png');
   background-size: cover;
   background-position: center;
   background-repeat: no-repeat;
diff --git a/src/app/planet/manage/page.tsx b/src/app/planet/manage/page.tsx
index 3d24ab6e..44593af0 100644
--- a/src/app/planet/manage/page.tsx
+++ b/src/app/planet/manage/page.tsx
@@ -11,6 +11,7 @@ import { DragDropContext, Droppable, Draggable } from 'react-beautiful-dnd';
 import {
   deleteSpaces,
   getSpaceList,
+  putMainSpace,
   putSpacesOrder
 } from '@/api/planet/space/space';
 import { useToast } from '@/hooks/useToast';
@@ -104,13 +105,19 @@ const PlanetManagePage = () => {
   };
 
   /* 홈(메인) 행성 고정 */
-  const handleFixMainPlanet = () => {
+  const handleFixMainPlanet = async () => {
     const selectedPlanet = planets?.filter((planet) =>
       selectedId.includes(planet.spaceId)
     );
-
-    /* TODO: 선택 행성 (selectedId) 메인 행성으로 변경 API 연동 */
-
+    await putMainSpace(selectedId);
+    setPlanets(
+      planets.map((planet) =>
+        planet.spaceId === selectedId
+          ? { ...planet, isMainSpace: true }
+          : { ...planet, isMainSpace: false }
+      )
+    );
+    setViewSpaceId(null);
     setIsBottomUp(false);
     showToast(`${selectedPlanet[0]?.spaceName} 행성을 홈으로 고정했어요`, {
       icon: false,
diff --git a/src/app/signup/complete/page.tsx b/src/app/signup/complete/page.tsx
index 34697cf6..db62f2ee 100644
--- a/src/app/signup/complete/page.tsx
+++ b/src/app/signup/complete/page.tsx
@@ -1,22 +1,22 @@
-"use client";
+'use client';
 
-import Button from "@/components/common/Button";
-import Loader, { LoaderContainer } from "@/components/common/Loader";
-import NavigatorBar from "@/components/common/NavigatorBar";
-import { useRouter, useSearchParams } from "next/navigation";
-import { Suspense } from "react";
-import styled from "styled-components";
+import Button from '@/components/common/Button';
+import Loader, { LoaderContainer } from '@/components/common/Loader';
+import NavigatorBar from '@/components/common/NavigatorBar';
+import { useRouter, useSearchParams } from 'next/navigation';
+import { Suspense } from 'react';
+import styled from 'styled-components';
 
 const Signup = () => {
   const router = useRouter();
   const searchParams = useSearchParams();
-  const url = searchParams.get("url");
+  const url = searchParams.get('url');
 
   const handleButtonClick = () => {
     if (url) {
       router.push(`/verify/letter?url=${url}`);
     } else {
-      router.push("/onboarding");
+      router.push('/onboarding');
     }
   };
   return (
@@ -29,7 +29,7 @@ const Signup = () => {
             <br /> 레터링에 오신 걸 환영해요
           </HeaderTitle>
           <HeaderSubTitle>
-            편지에 담긴 진심으로 나만의 우주를 채워보세요!
+            편지에 담긴 진심으로 나의 스페이스를 채워보세요!
           </HeaderSubTitle>
         </Header>
         <ImageWrapper>
@@ -39,7 +39,7 @@ const Signup = () => {
       <Wrapper>
         <Button
           buttonType="primary"
-          text={url ? "나에게 온 편지 열기" : "나의 스페이스에 접속하기"}
+          text={url ? '나에게 온 편지 열기' : '나의 스페이스에 접속하기'}
           onClick={handleButtonClick}
         ></Button>
       </Wrapper>
@@ -72,7 +72,7 @@ const Container = styled.div`
   flex-direction: column;
   //overflow: scroll;
   justify-content: space-between;
-  background-image: url("/assets/signup/signup_bg.png");
+  background-image: url('/assets/signup/signup_bg.png');
   background-size: cover;
   background-position: center;
   background-repeat: no-repeat;
diff --git a/src/app/signup/page.tsx b/src/app/signup/page.tsx
index 98badbeb..ccb404fc 100644
--- a/src/app/signup/page.tsx
+++ b/src/app/signup/page.tsx
@@ -1,5 +1,6 @@
 'use client';
 
+import { theme } from '@/styles/theme';
 import styled from 'styled-components';
 
 export default function Signup() {
@@ -10,6 +11,6 @@ const Container = styled.div`
   display: flex;
   min-height: 100%;
   padding: 20px;
-  color: white;
-  background: #060812;
+  color: ${theme.colors.white};
+  background: ${theme.colors.bg};
 `;
diff --git a/src/app/signup/step1/page.tsx b/src/app/signup/step1/page.tsx
index 0810d65f..7dc10c01 100644
--- a/src/app/signup/step1/page.tsx
+++ b/src/app/signup/step1/page.tsx
@@ -1,22 +1,22 @@
-"use client";
+'use client';
 
-import Button from "@/components/common/Button";
-import Check from "@/components/common/Check";
-import { Suspense, useState } from "react";
-import styled from "styled-components";
-import { useRouter, useSearchParams } from "next/navigation";
-import NavigatorBar from "@/components/common/NavigatorBar";
-import { userInfo } from "@/recoil/signupStore";
-import { useRecoilState } from "recoil";
-import { links } from "@/styles/theme";
-import Loader, { LoaderContainer } from "@/components/common/Loader";
-import { useToast } from "@/hooks/useToast";
+import Button from '@/components/common/Button';
+import Check from '@/components/common/Check';
+import { Suspense, useState } from 'react';
+import styled from 'styled-components';
+import { useRouter, useSearchParams } from 'next/navigation';
+import NavigatorBar from '@/components/common/NavigatorBar';
+import { userInfo } from '@/recoil/signupStore';
+import { useRecoilState } from 'recoil';
+import { links } from '@/styles/theme';
+import Loader, { LoaderContainer } from '@/components/common/Loader';
+import { useToast } from '@/hooks/useToast';
 
 const SignupStep1 = () => {
   const router = useRouter();
   const { showToast } = useToast();
   const searchParams = useSearchParams();
-  const url = searchParams.get("url");
+  const url = searchParams.get('url');
   const [user, setUser] = useRecoilState(userInfo);
   const [isAllChecked, setIsAllChecked] = useState(false);
   const [isSerivceChecked, setIsServiceChecked] = useState(false);
@@ -28,34 +28,34 @@ const SignupStep1 = () => {
       if (url) {
         router.push(`/signup/step2?url=${url}`);
       } else {
-        router.push("/signup/step2");
+        router.push('/signup/step2');
       }
 
       setUser({
         ...user,
         marketingPermission: isMarketingChecked,
         servicePermission: isSerivceChecked,
-        privatePermission: isPersonalChecked,
+        privatePermission: isPersonalChecked
       });
     } else {
-      showToast("필수 항목에 동의해주세요!", {
+      showToast('필수 항목에 동의해주세요!', {
         icon: true,
         close: false,
-        bottom: "120px",
+        bottom: '120px'
       });
     }
   };
 
   const handleCheckChange = (type: string) => {
     switch (type) {
-      case "all":
+      case 'all':
         const newAllChecked = !isAllChecked;
         setIsAllChecked(newAllChecked);
         setIsServiceChecked(newAllChecked);
         setIsPersonalChecked(newAllChecked);
         setIsMarketingChecked(newAllChecked);
         break;
-      case "service":
+      case 'service':
         const newServiceChecked = !isSerivceChecked;
         setIsServiceChecked(newServiceChecked);
         updateAllChecked(
@@ -64,7 +64,7 @@ const SignupStep1 = () => {
           isMarketingChecked
         );
         break;
-      case "personal":
+      case 'personal':
         const newPersonalChecked = !isPersonalChecked;
         setIsPersonalChecked(newPersonalChecked);
         updateAllChecked(
@@ -73,7 +73,7 @@ const SignupStep1 = () => {
           isMarketingChecked
         );
         break;
-      case "marketing":
+      case 'marketing':
         const newMarketingChecked = !isMarketingChecked;
         setIsMarketingChecked(newMarketingChecked);
         updateAllChecked(
@@ -113,7 +113,7 @@ const SignupStep1 = () => {
               <Check
                 checkType="box"
                 checked={isAllChecked}
-                onChange={() => handleCheckChange("all")}
+                onChange={() => handleCheckChange('all')}
                 label="약관 전체 동의"
                 sublabel="(선택사항 포함)"
               />
@@ -122,7 +122,7 @@ const SignupStep1 = () => {
               <Check
                 checkType="default"
                 checked={isSerivceChecked}
-                onChange={() => handleCheckChange("service")}
+                onChange={() => handleCheckChange('service')}
                 label="서비스 이용 약관"
                 sublabel="(필수)"
               />
@@ -137,7 +137,7 @@ const SignupStep1 = () => {
               <Check
                 checkType="default"
                 checked={isPersonalChecked}
-                onChange={() => handleCheckChange("personal")}
+                onChange={() => handleCheckChange('personal')}
                 label="개인정보 수집 및 이용 동의"
                 sublabel="(필수)"
               />
@@ -152,7 +152,7 @@ const SignupStep1 = () => {
               <Check
                 checkType="default"
                 checked={isMarketingChecked}
-                onChange={() => handleCheckChange("marketing")}
+                onChange={() => handleCheckChange('marketing')}
                 label="마케팅 수신 동의"
                 sublabel="(선택)"
               />
@@ -169,6 +169,7 @@ const SignupStep1 = () => {
       <Button
         buttonType="primary"
         text="다음"
+        disabled={!isSerivceChecked || !isPersonalChecked}
         onClick={handleButtonClick}
       ></Button>
     </Container>
diff --git a/src/app/signup/step2/page.tsx b/src/app/signup/step2/page.tsx
index ca1a9f0d..0f5c1c90 100644
--- a/src/app/signup/step2/page.tsx
+++ b/src/app/signup/step2/page.tsx
@@ -103,6 +103,7 @@ const SignupStep2 = () => {
           isOpen={isBottomUp}
           handleOpen={handleBottomUpChange}
           onConfirm={handleLoginClick}
+          confirmText="네, 맞아요"
         />
       )}
       <MainWrapper>
@@ -111,10 +112,10 @@ const SignupStep2 = () => {
           <HeaderTitle>
             회원가입을 하기 전
             <br />
-            먼저 본인 인증이 필요해요
+            먼저 실명 입력이 필요해요
           </HeaderTitle>
           <HeaderSubTitle>
-            별명이 아닌 정확한 실명을 입력해주세요
+            반드시 ‘성+이름’의 실명으로 작성해주세요
           </HeaderSubTitle>
         </Header>
         <InputWrapper>
@@ -122,7 +123,7 @@ const SignupStep2 = () => {
             inputType="signup"
             value={name}
             onChange={setName}
-            placeholder="ex)홍길동"
+            placeholder="ex) 홍길동"
             isValid={isVaild}
             isValidChange={setIsVaild}
             errorMessage="단독 자음, 모음만 쓸 수 없어요 (ex) ㄱ, ㅏ)"
@@ -136,6 +137,7 @@ const SignupStep2 = () => {
         <Button
           buttonType="primary"
           text="다음"
+          disabled={!name}
           onClick={handleButtonClick}
         ></Button>
       </ButtonWrapper>
diff --git a/src/components/planet/PlanetList.tsx b/src/components/planet/PlanetList.tsx
index ffc70cf4..105dad67 100644
--- a/src/components/planet/PlanetList.tsx
+++ b/src/components/planet/PlanetList.tsx
@@ -83,8 +83,8 @@ export default PlanetList;
 
 const Box = styled.div`
   width: 100%;
+  height: 68px;
   display: flex;
-  padding: 14px 12px 14px 16px;
   flex-direction: column;
   align-items: flex-start;
   gap: 10px;
@@ -140,8 +140,8 @@ const MainLabel = styled.div`
 `;
 
 const IconButton = styled.button`
-  width: 24px;
-  height: 24px;
+  width: 30px;
+  height: 40px;
   display: flex;
   align-items: center;
   justify-content: center;