diff --git a/package.json b/package.json
index 5c95387..bb1727b 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@ainize-team/ainize-js",
-  "version": "1.0.3",
+  "version": "1.0.4",
   "main": "dist/ainize.js",
   "types": "dist/ainize.d.ts",
   "scripts": {
diff --git a/src/controllers/serviceController.ts b/src/controllers/serviceController.ts
index 1c97646..f5bbfbe 100644
--- a/src/controllers/serviceController.ts
+++ b/src/controllers/serviceController.ts
@@ -17,13 +17,18 @@ export default class ServiceController {
     return ServiceController.instance;
   }
 
-  async isRunning(serviceName: string): Promise<void> {
-    const isRunning = await this.ain.getValue(Path.app(serviceName).status());
-    if(isRunning !== ContainerStatus.RUNNING) {
-      throw new Error('Service is not running');
+  async checkRunning(serviceName: string): Promise<void> {
+    const isRunning = await this.isRunning(serviceName);
+    if (!isRunning) {
+      throw new Error('Service is not running.');
     }
   }
 
+  async isRunning(serviceName: string): Promise<boolean> {
+    const runningStatus = await this.ain.getValue(Path.app(serviceName).status());
+    return runningStatus === ContainerStatus.RUNNING ? true : false;
+  }
+
   // TODO(woojae): implement this
   async getInformation(serviceName: string): Promise<any> {
     return await 'information of service';
@@ -43,7 +48,7 @@ export default class ServiceController {
   }
 
   async chargeCredit(serviceName: string, amount: number): Promise<string> {
-    this.isRunning(serviceName);
+    this.checkRunning(serviceName);
     const transferKey = Date.now();
     const userAddress = this.ain.getAddress(); 
     const depositAddress = await this.getDepositAddress(serviceName);
@@ -73,7 +78,7 @@ export default class ServiceController {
   }
 
   async request(serviceName: string, requestData: any) : Promise<any> {
-    this.isRunning(serviceName);
+    this.checkRunning(serviceName);
     const result = await new Promise(async (resolve, reject) => {
       const requestKey = Date.now();
       const requesterAddress = this.ain.getAddress();
diff --git a/src/service.ts b/src/service.ts
index 1c86ecf..24239da 100644
--- a/src/service.ts
+++ b/src/service.ts
@@ -10,12 +10,13 @@ export default class Service {
   }
 
   /**
-   * Check if service is running. It throws error when service is not running.
+   * Gets whether the service is running or not.
+   * @returns {Promise<boolean>}
    */
   async isRunning() {
     return await this.serviceController.isRunning(this.serviceName);
   }
-
+  
   /**
    * Get service information. not implemented yet.
    * @returns {string} Service information.