diff --git a/src/main/java/NextLevel/demo/project/community/controller/ProjectCommunityController.java b/src/main/java/NextLevel/demo/project/community/controller/ProjectCommunityController.java
index 226cca7..a2fdc5f 100644
--- a/src/main/java/NextLevel/demo/project/community/controller/ProjectCommunityController.java
+++ b/src/main/java/NextLevel/demo/project/community/controller/ProjectCommunityController.java
@@ -2,6 +2,7 @@
 
 import NextLevel.demo.common.SuccessResponse;
 import NextLevel.demo.project.community.dto.request.SaveCommunityDto;
+import NextLevel.demo.project.community.service.ProjectCommunityAnswerService;
 import NextLevel.demo.project.community.dto.response.ResponseCommunityListDto;
 import NextLevel.demo.project.community.service.ProjectCommunityAskService;
 import NextLevel.demo.util.jwt.JWTUtil;
@@ -18,35 +19,65 @@
 @RequiredArgsConstructor
 public class ProjectCommunityController {
 
-    private final ProjectCommunityAskService communityService;
+    private final ProjectCommunityAskService askService;
+    private final ProjectCommunityAnswerService answerService;
+
+    // ask 관련
 
     // list
     @GetMapping("/public/project/{projectId}/community")
     public ResponseEntity getProjectCommunity(@PathVariable Long projectId) {
-        return ResponseEntity.ok().body(new SuccessResponse("success", new ResponseCommunityListDto(communityService.selectAll(projectId))));
+        return ResponseEntity.ok().body(new SuccessResponse("success", new ResponseCommunityListDto(askService.selectAll(projectId))));
     }
 
-    // 생성만
+    // 생성
     @PostMapping("/api1/project/{projectId}/community")
-    public ResponseEntity<?> saveProjectCommunity(@PathVariable("projectId") Long projectId, @RequestBody @Valid SaveCommunityDto dto) {
+    public ResponseEntity<?> saveProjectCommunityAsk(@PathVariable("projectId") Long projectId, @RequestBody @Valid SaveCommunityDto dto) {
         dto.setUserId(JWTUtil.getUserIdFromSecurityContext());
         dto.setId(projectId);
-        communityService.create(dto);
+        askService.create(dto);
         return ResponseEntity.status(HttpStatus.OK).body(new SuccessResponse("success", null));
     }
 
     // 수정
     @PostMapping("/api1/project/community/{communityId}")
-    public ResponseEntity<?> updateProjectCommunity(@PathVariable("communityId") Long communityId, @RequestBody @Valid SaveCommunityDto dto) {
+    public ResponseEntity<?> updateProjectCommunityAsk(@PathVariable("communityId") Long communityId, @RequestBody @Valid SaveCommunityDto dto) {
         dto.setUserId(JWTUtil.getUserIdFromSecurityContext());
         dto.setId(communityId);
-        communityService.update(dto);
+        askService.update(dto);
         return ResponseEntity.status(HttpStatus.OK).body(new SuccessResponse("success", null));
     }
 
     @DeleteMapping("/api1/project/community/{communityId}")
     public ResponseEntity<?> deleteProjectCommunity(@PathVariable("communityId") Long communityId) {
-        communityService.delete(communityId,JWTUtil.getUserIdFromSecurityContext());
+        askService.delete(communityId,JWTUtil.getUserIdFromSecurityContext());
+        return ResponseEntity.status(HttpStatus.OK).body(new SuccessResponse("success", null));
+    }
+
+    // answer 관련
+
+    // 생성
+    @PostMapping("/api1/project/{askId}/community/answer")
+    public ResponseEntity<?> saveProjectCommunityAnswer(@PathVariable("askId") Long askId, @RequestBody @Valid SaveCommunityDto dto) {
+        dto.setUserId(JWTUtil.getUserIdFromSecurityContext());
+        dto.setId(askId);
+        answerService.addAnswer(dto);
         return ResponseEntity.status(HttpStatus.OK).body(new SuccessResponse("success", null));
     }
+
+    // 수정
+    @PostMapping("/api1/project/community/{answerId}/answer")
+    public ResponseEntity<?> updateProjectCommunityAnswer(@PathVariable("answerId") Long answerId, @RequestBody @Valid SaveCommunityDto dto) {
+        dto.setUserId(JWTUtil.getUserIdFromSecurityContext());
+        dto.setId(answerId);
+        answerService.updateAnswer(dto);
+        return ResponseEntity.status(HttpStatus.OK).body(new SuccessResponse("success", null));
+    }
+
+    @DeleteMapping("/api1/project/community/{answerId}/answer")
+    public ResponseEntity<?> deleteProjectCommunityAnswer(@PathVariable("answerId") Long answerId) {
+        answerService.deleteAnswer(answerId,JWTUtil.getUserIdFromSecurityContext());
+        return ResponseEntity.status(HttpStatus.OK).body(new SuccessResponse("success", null));
+    }
+
 }
diff --git a/src/main/java/NextLevel/demo/project/community/entity/ProjectCommunityAnswerEntity.java b/src/main/java/NextLevel/demo/project/community/entity/ProjectCommunityAnswerEntity.java
index ee3f2d6..5e5292b 100644
--- a/src/main/java/NextLevel/demo/project/community/entity/ProjectCommunityAnswerEntity.java
+++ b/src/main/java/NextLevel/demo/project/community/entity/ProjectCommunityAnswerEntity.java
@@ -1,6 +1,7 @@
 package NextLevel.demo.project.community.entity;
 
 import NextLevel.demo.BasedEntity;
+import NextLevel.demo.project.community.dto.request.SaveCommunityDto;
 import NextLevel.demo.user.entity.UserEntity;
 import jakarta.persistence.*;
 import lombok.AllArgsConstructor;
@@ -31,4 +32,9 @@ public class ProjectCommunityAnswerEntity extends BasedEntity {
     @JoinColumn(name = "ask_id", nullable = false)
     private ProjectCommunityAskEntity ask;
 
+    public void update(SaveCommunityDto dto) {
+        if(dto.getContent() != null && !dto.getContent().isEmpty())
+            this.content = dto.getContent();
+    }
+
 }
diff --git a/src/main/java/NextLevel/demo/project/community/entity/ProjectCommunityAskEntity.java b/src/main/java/NextLevel/demo/project/community/entity/ProjectCommunityAskEntity.java
index fc24aa3..b1ba2b1 100644
--- a/src/main/java/NextLevel/demo/project/community/entity/ProjectCommunityAskEntity.java
+++ b/src/main/java/NextLevel/demo/project/community/entity/ProjectCommunityAskEntity.java
@@ -36,7 +36,7 @@ public class ProjectCommunityAskEntity extends BasedEntity {
     @JoinColumn(name = "user_id", nullable = false)
     private UserEntity user;
 
-    @OneToOne(mappedBy = "ask")
+    @OneToOne(mappedBy = "ask", cascade = {CascadeType.REMOVE})
     private ProjectCommunityAnswerEntity answer;
 
     public void update(SaveCommunityDto dto) {
@@ -44,4 +44,6 @@ public void update(SaveCommunityDto dto) {
             this.content = dto.getContent();
     }
 
+    public void setNoAnswer() { answer = null; }
+
 }
diff --git a/src/main/java/NextLevel/demo/project/community/service/ProjectCommunityAnswerService.java b/src/main/java/NextLevel/demo/project/community/service/ProjectCommunityAnswerService.java
new file mode 100644
index 0000000..343e61d
--- /dev/null
+++ b/src/main/java/NextLevel/demo/project/community/service/ProjectCommunityAnswerService.java
@@ -0,0 +1,68 @@
+package NextLevel.demo.project.community.service;
+
+import NextLevel.demo.exception.CustomException;
+import NextLevel.demo.exception.ErrorCode;
+import NextLevel.demo.project.community.dto.request.SaveCommunityDto;
+import NextLevel.demo.project.community.entity.ProjectCommunityAnswerEntity;
+import NextLevel.demo.project.community.entity.ProjectCommunityAskEntity;
+import NextLevel.demo.project.community.repository.ProjectCommunityAnswerRepository;
+import NextLevel.demo.project.community.repository.ProjectCommunityAskRepository;
+import NextLevel.demo.project.project.service.ProjectValidateService;
+import NextLevel.demo.user.entity.UserEntity;
+import NextLevel.demo.user.service.UserValidateService;
+import lombok.RequiredArgsConstructor;
+import org.springframework.stereotype.Service;
+import org.springframework.transaction.annotation.Transactional;
+
+@Service
+@RequiredArgsConstructor
+public class ProjectCommunityAnswerService {
+
+    private final ProjectValidateService projectValidateService;
+    private final UserValidateService userValidateService;
+
+    private final ProjectCommunityAnswerRepository projectCommunityAnswerRepository;
+    private final ProjectCommunityAskRepository projectCommunityAskRepository;
+
+    @Transactional
+    public void addAnswer(SaveCommunityDto dto) {
+        Long askId = dto.getId();
+        ProjectCommunityAskEntity ask = projectCommunityAskRepository.findById(askId).orElseThrow(
+                ()->{return new CustomException(ErrorCode.NOT_FOUND, "community");}
+        );
+        UserEntity user = userValidateService.getUserInfo(dto.getUserId());
+
+        projectValidateService.validateAuthor(ask.getProject(), user);
+
+        if(ask.getAnswer() != null) {
+            dto.setId(ask.getAnswer().getId());
+            updateAnswer(dto);
+            return;
+        }
+
+        projectCommunityAnswerRepository.save(dto.toAnswerEntity(user, ask));
+    }
+
+    @Transactional
+    public void updateAnswer(SaveCommunityDto dto) {
+        Long answerId = dto.getId();
+        ProjectCommunityAnswerEntity answer = projectCommunityAnswerRepository.findById(answerId).orElseThrow(
+                ()->{return new CustomException(ErrorCode.NOT_FOUND, "community");}
+        );
+        UserEntity user = userValidateService.getUserInfo(dto.getUserId());
+        projectValidateService.validateAuthor(answer.getAsk().getProject(), user);
+        answer.update(dto);
+    }
+
+    @Transactional
+    public void deleteAnswer(Long answerId, Long userId) {
+        ProjectCommunityAnswerEntity answer = projectCommunityAnswerRepository.findById(answerId).orElseThrow(
+                ()->{return new CustomException(ErrorCode.NOT_FOUND, "community");}
+        );
+        UserEntity user = userValidateService.getUserInfo(userId);
+        projectValidateService.validateAuthor(answer.getAsk().getProject(), user);
+        answer.getAsk().setNoAnswer();
+        projectCommunityAnswerRepository.deleteById(answerId);
+    }
+
+}
diff --git a/src/main/java/NextLevel/demo/project/project/service/ProjectValidateService.java b/src/main/java/NextLevel/demo/project/project/service/ProjectValidateService.java
index c2d63ed..b8ecb82 100644
--- a/src/main/java/NextLevel/demo/project/project/service/ProjectValidateService.java
+++ b/src/main/java/NextLevel/demo/project/project/service/ProjectValidateService.java
@@ -4,6 +4,7 @@
 import NextLevel.demo.exception.ErrorCode;
 import NextLevel.demo.project.project.entity.ProjectEntity;
 import NextLevel.demo.project.project.repository.ProjectRepository;
+import NextLevel.demo.user.entity.UserEntity;
 import lombok.RequiredArgsConstructor;
 import org.springframework.stereotype.Service;
 
@@ -20,9 +21,21 @@ public ProjectEntity getProjectEntity(Long id) {
 
     public ProjectEntity validateAuthor(Long projectId, Long userId) {
         ProjectEntity project = getProjectEntity(projectId);
-        if(project.getUser().getId() != userId){
+        if(!project.getUser().getId().equals(userId)){
             throw new CustomException(ErrorCode.NOT_AUTHOR);
         }
         return project;
     }
+
+    public void validateAuthor(ProjectEntity project, Long userId) {
+        if(!project.getUser().getId().equals(userId)){
+            throw new CustomException(ErrorCode.NOT_AUTHOR);
+        }
+    }
+
+    public void validateAuthor(ProjectEntity project, UserEntity user) {
+        if(!project.getUser().getId().equals(user.getId())){
+            throw new CustomException(ErrorCode.NOT_AUTHOR);
+        }
+    }
 }