diff --git a/logbat/src/main/java/info/logbat/domain/log/application/LogService.java b/logbat/src/main/java/info/logbat/domain/log/application/LogService.java
index 002fcaa..42e9044 100644
--- a/logbat/src/main/java/info/logbat/domain/log/application/LogService.java
+++ b/logbat/src/main/java/info/logbat/domain/log/application/LogService.java
@@ -3,7 +3,9 @@
 import info.logbat.domain.log.application.payload.request.CreateLogServiceRequest;
 import info.logbat.domain.log.domain.Log;
 import info.logbat.domain.log.repository.LogRepository;
+import info.logbat.domain.project.repository.AppJpaRepository;
 import java.time.LocalDateTime;
+import java.util.UUID;
 import lombok.RequiredArgsConstructor;
 import org.springframework.stereotype.Service;
 
@@ -12,16 +14,29 @@
 public class LogService {
 
   private final LogRepository logRepository;
+  private final AppJpaRepository appJpaRepository;
 
   public long saveLog(CreateLogServiceRequest request) {
-    String appKey = request.appKey();
     String level = request.level();
     String data = request.data();
     LocalDateTime timestamp = request.timestamp();
-    // TODO Log 저장 전 Application ID 체크 로직 추가 필요
+
+    String appKey = getAppKey(request.appKey());
 
     Log log = Log.of(appKey, level, data, timestamp);
 
     return logRepository.save(log);
   }
+
+  private String getAppKey(String appKey) {
+    try {
+      UUID appKeyUuid = UUID.fromString(appKey);
+      if (appJpaRepository.existsByToken(appKeyUuid)) {
+        return appKeyUuid.toString();
+      }
+    } catch (IllegalArgumentException e) {
+      throw new IllegalArgumentException("잘못된 형식의 Application Key 입니다.");
+    }
+    throw new IllegalArgumentException("존재하지 않는 Application Key 입니다.");
+  }
 }
diff --git a/logbat/src/main/java/info/logbat/domain/project/repository/AppJpaRepository.java b/logbat/src/main/java/info/logbat/domain/project/repository/AppJpaRepository.java
index f990ef5..b3503cc 100644
--- a/logbat/src/main/java/info/logbat/domain/project/repository/AppJpaRepository.java
+++ b/logbat/src/main/java/info/logbat/domain/project/repository/AppJpaRepository.java
@@ -11,9 +11,11 @@
 @Repository
 public interface AppJpaRepository extends JpaRepository<App, Long> {
 
-    Optional<App> findByToken(@NonNull UUID token);
+  Optional<App> findByToken(@NonNull UUID token);
 
-    Optional<App> findByProject_IdAndId(@NonNull Long id, @NonNull Long id1);
+  Optional<App> findByProject_IdAndId(@NonNull Long id, @NonNull Long id1);
 
-    List<App> findByProject_Id(@NonNull Long id);
+  List<App> findByProject_Id(@NonNull Long id);
+
+  boolean existsByToken(@NonNull UUID token);
 }
diff --git a/logbat/src/test/java/info/logbat/domain/log/application/LogServiceTest.java b/logbat/src/test/java/info/logbat/domain/log/application/LogServiceTest.java
index dc7a0fd..a48363d 100644
--- a/logbat/src/test/java/info/logbat/domain/log/application/LogServiceTest.java
+++ b/logbat/src/test/java/info/logbat/domain/log/application/LogServiceTest.java
@@ -1,11 +1,17 @@
 package info.logbat.domain.log.application;
 
 import static org.assertj.core.api.Assertions.assertThat;
+import static org.assertj.core.api.Assertions.assertThatThrownBy;
 
 import info.logbat.domain.log.application.payload.request.CreateLogServiceRequest;
 import info.logbat.domain.log.domain.Log;
 import info.logbat.domain.log.domain.enums.Level;
 import info.logbat.domain.log.repository.LogRepository;
+import info.logbat.domain.project.domain.App;
+import info.logbat.domain.project.domain.Project;
+import info.logbat.domain.project.domain.enums.AppType;
+import info.logbat.domain.project.repository.AppJpaRepository;
+import info.logbat.domain.project.repository.ProjectJpaRepository;
 import java.time.LocalDateTime;
 import java.util.Optional;
 import java.util.UUID;
@@ -28,17 +34,34 @@ class LogServiceTest {
   @Autowired
   private LogRepository logRepository;
 
-  private static final String 앱_키_문자열 = UUID.randomUUID().toString();
+  @Autowired
+  private ProjectJpaRepository projectJpaRepository;
+
+  @Autowired
+  private AppJpaRepository appJpaRepository;
 
   @DisplayName("Log를 저장할 수 있다.")
   @Test
   void saveLog() {
     // given
+    String 프로젝트_이름 = "테스트_프로젝트";
+    Project 프로젝트 = Project.from(프로젝트_이름);
+
+    AppType 앱_타입 = AppType.JAVA;
+
+    App 앱 = App.of(프로젝트, 앱_타입);
+
+    projectJpaRepository.save(프로젝트);
+    appJpaRepository.save(앱);
+
+    UUID 앱_키 = 앱.getToken();
+
     String 로그_레벨 = "INFO";
     String 로그_데이터 = "테스트_로그_데이터";
     LocalDateTime 타임스탬프 = LocalDateTime.of(2021, 1, 1, 0, 0, 0);
 
-    CreateLogServiceRequest 요청_DTO = new CreateLogServiceRequest(앱_키_문자열, 로그_레벨, 로그_데이터, 타임스탬프);
+    CreateLogServiceRequest 요청_DTO = new CreateLogServiceRequest(앱_키.toString(), 로그_레벨, 로그_데이터,
+        타임스탬프);
 
     // when
     long 저장된_ID = logService.saveLog(요청_DTO);
@@ -49,7 +72,43 @@ void saveLog() {
     assertThat(찾은_로그).isPresent()
         .get()
         .extracting("logId", "appKey", "level", "data.value", "timestamp")
-        .contains(저장된_ID, 앱_키_문자열, Level.INFO, "테스트_로그_데이터", 타임스탬프);
+        .contains(저장된_ID, 앱_키.toString(), Level.INFO, "테스트_로그_데이터", 타임스탬프);
+  }
+
+  @DisplayName("존재하지 않는 Application Key로 Log를 저장할 수 없다.")
+  @Test
+  void saveLogWithNonExistentAppKey() {
+    // given
+    String 존재하지_않는_앱_키_문자열 = UUID.randomUUID().toString();
+    String 로그_레벨 = "INFO";
+    String 로그_데이터 = "테스트_로그_데이터";
+    LocalDateTime 타임스탬프 = LocalDateTime.of(2021, 1, 1, 0, 0, 0);
+
+    CreateLogServiceRequest 요청_DTO = new CreateLogServiceRequest(존재하지_않는_앱_키_문자열, 로그_레벨, 로그_데이터,
+        타임스탬프);
+
+    // when & then
+    assertThatThrownBy(() -> logService.saveLog(요청_DTO))
+        .isInstanceOf(IllegalArgumentException.class)
+        .hasMessage("존재하지 않는 Application Key 입니다.");
+  }
+
+  @DisplayName("잘못된 형태의 Application Key로 Log를 저장할 수 없다.")
+  @Test
+  void saveLogWithInvalidAppKey() {
+    // given
+    String 잘못된_앱_키_문자열 = "잘못된_앱_키_문자열";
+    String 로그_레벨 = "INFO";
+    String 로그_데이터 = "테스트_로그_데이터";
+    LocalDateTime 타임스탬프 = LocalDateTime.of(2021, 1, 1, 0, 0, 0);
+
+    CreateLogServiceRequest 요청_DTO = new CreateLogServiceRequest(잘못된_앱_키_문자열, 로그_레벨, 로그_데이터,
+        타임스탬프);
+
+    // when & then
+    assertThatThrownBy(() -> logService.saveLog(요청_DTO))
+        .isInstanceOf(IllegalArgumentException.class)
+        .hasMessage("잘못된 형식의 Application Key 입니다.");
   }
 
 }
\ No newline at end of file