diff --git a/src/main/java/com/pawwithu/connectdog/domain/application/entity/Application.java b/src/main/java/com/pawwithu/connectdog/domain/application/entity/Application.java
index a7c2e8fd..8f1494bf 100644
--- a/src/main/java/com/pawwithu/connectdog/domain/application/entity/Application.java
+++ b/src/main/java/com/pawwithu/connectdog/domain/application/entity/Application.java
@@ -26,7 +26,7 @@ public class Application extends BaseTimeEntity {
     private String phone; // 전화번호
     @Column(length = 200, nullable = false)
     private String content; // 전달 및 문의사항
-    @OneToOne(fetch = FetchType.LAZY)
+    @ManyToOne(fetch = FetchType.LAZY)
     @JoinColumn(name = "post_id", nullable = false)
     private Post post;  // 공고 id
     @ManyToOne(fetch = FetchType.LAZY)
diff --git a/src/main/java/com/pawwithu/connectdog/domain/application/repository/ApplicationRepository.java b/src/main/java/com/pawwithu/connectdog/domain/application/repository/ApplicationRepository.java
index 1ebe1876..1213af99 100644
--- a/src/main/java/com/pawwithu/connectdog/domain/application/repository/ApplicationRepository.java
+++ b/src/main/java/com/pawwithu/connectdog/domain/application/repository/ApplicationRepository.java
@@ -1,6 +1,7 @@
 package com.pawwithu.connectdog.domain.application.repository;
 
 import com.pawwithu.connectdog.domain.application.entity.Application;
+import com.pawwithu.connectdog.domain.application.entity.ApplicationStatus;
 import com.pawwithu.connectdog.domain.volunteer.entity.Volunteer;
 import org.springframework.data.jpa.repository.JpaRepository;
 
@@ -15,5 +16,6 @@ public interface ApplicationRepository extends JpaRepository<Application, Long>
     Optional<Application> findByIdAndIntermediaryId(Long id, Long intermediaryId);
     Long countAllByPostId(Long id);
     List<Application> findByVolunteer(Volunteer volunteer);
+    Optional<Application> findByPostIdAndStatusNot(Long postId, ApplicationStatus status);
 
 }
diff --git a/src/main/java/com/pawwithu/connectdog/domain/application/repository/CustomApplicationRepository.java b/src/main/java/com/pawwithu/connectdog/domain/application/repository/CustomApplicationRepository.java
index 3e68017b..a8e024a6 100644
--- a/src/main/java/com/pawwithu/connectdog/domain/application/repository/CustomApplicationRepository.java
+++ b/src/main/java/com/pawwithu/connectdog/domain/application/repository/CustomApplicationRepository.java
@@ -21,7 +21,6 @@ public interface CustomApplicationRepository {
     List<ApplicationVolunteerCompletedResponse> getVolunteerCompletedApplications(Long volunteerId, Pageable pageable);
     List<ApplicationIntermediaryCompletedResponse> getIntermediaryCompletedApplications(Long intermediaryId, Pageable pageable);
     List<Tuple> getCountOfApplicationsByStatus(Long id);
-    boolean existsByPostIdAndPostStatus(Long postId);
     void updateExpiredApplications(LocalDate today);
     List<Application> getYesterdayExpiredApplications(LocalDate date);
     List<Application> getExpiredProgressingPosts(LocalDate date);
diff --git a/src/main/java/com/pawwithu/connectdog/domain/application/repository/impl/CustomApplicationRepositoryImpl.java b/src/main/java/com/pawwithu/connectdog/domain/application/repository/impl/CustomApplicationRepositoryImpl.java
index 5b05eb7c..11297ed2 100644
--- a/src/main/java/com/pawwithu/connectdog/domain/application/repository/impl/CustomApplicationRepositoryImpl.java
+++ b/src/main/java/com/pawwithu/connectdog/domain/application/repository/impl/CustomApplicationRepositoryImpl.java
@@ -5,6 +5,7 @@
 import com.pawwithu.connectdog.domain.application.entity.ApplicationStatus;
 import com.pawwithu.connectdog.domain.application.repository.CustomApplicationRepository;
 import com.pawwithu.connectdog.domain.post.entity.Post;
+import com.pawwithu.connectdog.domain.post.entity.PostStatus;
 import com.querydsl.core.Tuple;
 import com.querydsl.core.types.Projections;
 import com.querydsl.jpa.impl.JPAQueryFactory;
@@ -185,16 +186,6 @@ public List<Tuple> getCountOfApplicationsByStatus(Long id) {
                 .fetch();
     }
 
-    @Override
-    public boolean existsByPostIdAndPostStatus(Long postId) {
-        return queryFactory
-                .select(application)
-                .from(application)
-                .where(application.post.id.eq(postId)
-                        .and(application.status.ne(ApplicationStatus.REJECTED)))
-                .fetchOne() != null;
-    }
-
     // 어제 모집 마감된 신청 가져오기
     @Override
     public List<Application> getYesterdayExpiredApplications(LocalDate date) {
diff --git a/src/main/java/com/pawwithu/connectdog/domain/application/service/ApplicationService.java b/src/main/java/com/pawwithu/connectdog/domain/application/service/ApplicationService.java
index d688c8a7..1b60618f 100644
--- a/src/main/java/com/pawwithu/connectdog/domain/application/service/ApplicationService.java
+++ b/src/main/java/com/pawwithu/connectdog/domain/application/service/ApplicationService.java
@@ -50,13 +50,14 @@ public void volunteerApply(String email, Long postId, VolunteerApplyRequest requ
         // 이동봉사자
         Volunteer volunteer = volunteerRepository.findByEmail(email).orElseThrow(() -> new BadRequestException(VOLUNTEER_NOT_FOUND));
         // 공고
-        Post post = postRepository.findById(postId).orElseThrow(() -> new BadRequestException(POST_NOT_FOUND));
+        Post post = postRepository.findByIdAndStatus(postId, PostStatus.RECRUITING).orElseThrow(() -> new BadRequestException(POST_NOT_FOUND));
         // 이동봉사 중개
         Intermediary intermediary = post.getIntermediary();
-        // 해당 공고에 대한 신청이 이미 존재할 경우 - 신청 상태가 반려가 아닐 경우
-        if (customApplicationRepository.existsByPostIdAndPostStatus(postId)) {
-            throw new BadRequestException(ALREADY_EXIST_APPLICATION);
-        }
+        // 해당 공고에 대한 신청이 이미 존재할 경우 예외 처리 - 신청 상태가 반려가 아닐 경우
+        applicationRepository.findByPostIdAndStatusNot(postId, ApplicationStatus.REJECTED)
+                .ifPresent(application -> {
+                    throw new BadRequestException(ALREADY_EXIST_APPLICATION);
+                });
         // 공고 신청 저장
         Application application = request.toEntity(post, intermediary, volunteer);
         applicationRepository.save(application);
diff --git a/src/main/java/com/pawwithu/connectdog/domain/post/repository/PostRepository.java b/src/main/java/com/pawwithu/connectdog/domain/post/repository/PostRepository.java
index 5a501ce0..13ac399b 100644
--- a/src/main/java/com/pawwithu/connectdog/domain/post/repository/PostRepository.java
+++ b/src/main/java/com/pawwithu/connectdog/domain/post/repository/PostRepository.java
@@ -1,6 +1,7 @@
 package com.pawwithu.connectdog.domain.post.repository;
 
 import com.pawwithu.connectdog.domain.post.entity.Post;
+import com.pawwithu.connectdog.domain.post.entity.PostStatus;
 import org.springframework.data.jpa.repository.JpaRepository;
 
 import java.util.Optional;
@@ -8,4 +9,5 @@
 public interface PostRepository extends JpaRepository<Post, Long> {
 
     Optional<Post> findByIdAndIntermediaryId(Long id, Long intermediaryId);
+    Optional<Post> findByIdAndStatus(Long id, PostStatus postStatus);
 }