diff --git a/src/main/java/com/example/demo/app/domain/service/FixedCostService.java b/src/main/java/com/example/demo/app/domain/service/FixedCostService.java
new file mode 100644
index 0000000..52ba6fd
--- /dev/null
+++ b/src/main/java/com/example/demo/app/domain/service/FixedCostService.java
@@ -0,0 +1,16 @@
+package com.example.demo.app.domain.service;
+
+import java.util.List;
+
+import com.example.demo.app.domain.model.FixedCostModel;
+
+public interface FixedCostService {
+
+	public List<FixedCostModel> findAllByUserId(Long userId);
+	
+	public FixedCostModel save(FixedCostModel fixedCostModel);
+	
+	public void delete(Long fixedCostId);
+	
+	public FixedCostModel findById(Long fixedCostId);
+}
diff --git a/src/main/java/com/example/demo/app/domain/service/impl/FixedCostServiceImpl.java b/src/main/java/com/example/demo/app/domain/service/impl/FixedCostServiceImpl.java
new file mode 100644
index 0000000..e79597d
--- /dev/null
+++ b/src/main/java/com/example/demo/app/domain/service/impl/FixedCostServiceImpl.java
@@ -0,0 +1,48 @@
+package com.example.demo.app.domain.service.impl;
+
+import java.util.List;
+
+import org.springframework.stereotype.Service;
+
+import com.example.demo.app.domain.model.FixedCostModel;
+import com.example.demo.app.domain.service.FixedCostService;
+import com.example.demo.app.infra.repository.CategoryRepository;
+import com.example.demo.app.infra.repository.FixedCostRepository;
+import com.example.demo.app.infra.repository.UserRepository;
+
+import lombok.RequiredArgsConstructor;
+
+@Service
+@RequiredArgsConstructor
+public class FixedCostServiceImpl implements FixedCostService{
+
+
+	private final FixedCostRepository fixedCostRepository;
+	private final UserRepository userRepository;
+	private final CategoryRepository categoryRepository;
+	
+	
+	public List<FixedCostModel> findAllByUserId(Long userId) {
+		
+		return  FixedCostModel.convertFrom(fixedCostRepository.findByUserId(userId));
+		
+	}
+	
+	public FixedCostModel save(FixedCostModel fixedCostModel) {
+		
+		return  FixedCostModel.convertFrom(fixedCostRepository.save( FixedCostModel.convertTo(fixedCostModel, userRepository.findById(fixedCostModel.getUserId()).get(), categoryRepository.findById(fixedCostModel.getCategoryId()).get())));
+		
+	}
+	
+	public void delete(Long fixedCostId) {
+		
+		fixedCostRepository.deleteById(fixedCostId);
+		
+	}
+	
+	public FixedCostModel findById(Long fixedCostId) {
+		return  FixedCostModel.convertFrom(fixedCostRepository.findById(fixedCostId).get());
+	}
+	
+	
+}
diff --git a/src/main/java/com/example/demo/app/infra/repository/FixedCostRepository.java b/src/main/java/com/example/demo/app/infra/repository/FixedCostRepository.java
new file mode 100644
index 0000000..fe7279d
--- /dev/null
+++ b/src/main/java/com/example/demo/app/infra/repository/FixedCostRepository.java
@@ -0,0 +1,15 @@
+package com.example.demo.app.infra.repository;
+
+import java.util.List;
+
+import org.springframework.data.jpa.repository.JpaRepository;
+import org.springframework.data.jpa.repository.Query;
+
+import com.example.demo.app.infra.entity.FixedCostEntity;
+
+public interface FixedCostRepository extends JpaRepository<FixedCostEntity, Long> {
+
+	@Query("select f from FixedCostEntity f where f.userEntity.userId = :userId")
+	public List<FixedCostEntity> findByUserId(Long userId);
+
+}