diff --git a/sample-env.ts b/sample-env.ts
index 8d1eec17..568bcd72 100644
--- a/sample-env.ts
+++ b/sample-env.ts
@@ -7,6 +7,7 @@
 import {Env} from '@mytypes/env';
 
 export const env: Env = {
+  API_URL: '',
   GOOGLE_CLIENT_ID: '',
   GOOGLE_CLIENT_SECRET: '',
   SESSION_OPTION: {
diff --git a/src/types/env.d.ts b/src/types/env.d.ts
index 43c1ef28..cc2c91c7 100644
--- a/src/types/env.d.ts
+++ b/src/types/env.d.ts
@@ -7,6 +7,7 @@
 import {SessionOptions} from 'iron-session';
 
 export type Env = {
+  API_URL: string;
   GOOGLE_CLIENT_ID: string;
   GOOGLE_CLIENT_SECRET: string;
   SESSION_OPTION: SessionOptions;
diff --git a/src/utils/api/category.ts b/src/utils/api/category.ts
index 69c795be..8770fc8a 100644
--- a/src/utils/api/category.ts
+++ b/src/utils/api/category.ts
@@ -11,6 +11,7 @@ import {AllCategoryDataType, CategoryDataType} from '@mytypes/Category';
 import {NewCategory} from 'src/app/api/category/route';
 import {PutCategory} from 'src/app/api/category/[id]/route';
 import {tag_key} from './tag';
+import {env} from 'env';
 
 export const category_key = '/api/category';
 
@@ -18,11 +19,11 @@ export const mutate_category = (): Promise<void> => mutate(category_key);
 export const useAllCategoryData = useApiData<AllCategoryDataType[]>(category_key);
 
 export function fetch_category_data(id: number | string): Promise<CategoryDataType> {
-  return fetcher(`http://localhost:3009${category_key}/${id}`);
+  return fetcher(`${env.API_URL}${category_key}/${id}`);
 }
 // 特定のタグが付けられているすべてのカテゴリ
 export function fetch_category_with_spec_tag_data(tag_id: number | string): Promise<CategoryDataType> {
-  return fetcher(`http://localhost:3009${tag_key}/${tag_id}/all_category`);
+  return fetcher(`${env.API_URL}{tag_key}/${tag_id}/all_category`);
 }
 
 export async function new_category(data: NewCategory): AxiosPromise {
diff --git a/src/utils/api/history.ts b/src/utils/api/history.ts
index c9745657..7bb8c9d0 100644
--- a/src/utils/api/history.ts
+++ b/src/utils/api/history.ts
@@ -9,6 +9,7 @@ import axios, {AxiosPromise} from 'axios';
 import {fetcher, useApiData} from './common';
 import {AllHistory, History} from '@mytypes/ExamHistory';
 import {NewHistory} from 'src/app/api/history/route';
+import {env} from 'env';
 
 export const history_key = '/api/history';
 
@@ -16,7 +17,7 @@ export const mutate_history = (): Promise<void> => mutate(history_key);
 export const useAllHistory = useApiData<AllHistory[]>(history_key);
 
 export function fetch_history(id: string): Promise<History> {
-  return fetcher(`http://localhost:3009${history_key}/${id}`);
+  return fetcher(`${env.API_URL}${history_key}/${id}`);
 }
 
 export async function new_history(data: NewHistory): AxiosPromise {
diff --git a/src/utils/api/tag.ts b/src/utils/api/tag.ts
index 072445e8..438b3f3c 100644
--- a/src/utils/api/tag.ts
+++ b/src/utils/api/tag.ts
@@ -10,13 +10,14 @@ import {fetcher, useApiData} from './common';
 import TagData from '@mytypes/TagData';
 import {PutTag} from 'src/app/api/tag/[id]/route';
 import {PostTag} from 'src/app/api/tag/route';
+import {env} from 'env';
 
 export const tag_key = '/api/tag';
 
 export const mutate_tag = (): Promise<void> => mutate(tag_key);
 export const useTagData = useApiData<TagData[]>(tag_key);
 export function fetch_tag(): Promise<TagData[]> {
-  return fetcher(`http://localhost:3009${tag_key}`);
+  return fetcher(env.API_URL + tag_key);
 }
 
 export async function new_tag(data: PostTag): Promise<AxiosPromise> {