diff --git a/src/main/java/com/eactive/apim/portal/common/exception/PortalErrorController.java b/src/main/java/com/eactive/apim/portal/common/exception/PortalErrorController.java
index 86a2fe6..6337764 100644
--- a/src/main/java/com/eactive/apim/portal/common/exception/PortalErrorController.java
+++ b/src/main/java/com/eactive/apim/portal/common/exception/PortalErrorController.java
@@ -11,6 +11,8 @@ import org.springframework.web.servlet.ModelAndView;
 
 import javax.servlet.RequestDispatcher;
 import javax.servlet.http.HttpServletRequest;
+import java.io.PrintWriter;
+import java.io.StringWriter;
 
 /**
  * Created by Sungpil Hyun
@@ -43,6 +45,15 @@ public class PortalErrorController implements ErrorController {
                 modelAndView.addObject("errorTitle", resolveTitle(status));
                 modelAndView.addObject("errorDescription", resolveDescription(status));
                 modelAndView.addObject("errorMessage", resolveErrorMessage(request, status));
+                modelAndView.addObject("activeProfile", resolveActiveProfile());
+                // include-stacktrace=always(로컬 디버깅 프로파일)일 때만 화면에 스택 트레이스까지 노출
+                if (isErrorDetailEnabled()) {
+                    Throwable throwable = resolveThrowable(request);
+                    if (throwable != null) {
+                        modelAndView.addObject("errorException", throwable.getClass().getName());
+                        modelAndView.addObject("errorStackTrace", stackTraceAsString(throwable));
+                    }
+                }
             }
             return modelAndView;
         }
@@ -54,6 +65,37 @@ public class PortalErrorController implements ErrorController {
         return environment.acceptsProfiles(Profiles.of("prod"));
     }
 
+    /**
+     * server.error.include-stacktrace=always 인 경우에만 화면에 스택 트레이스를 노출한다.
+     * (로컬 디버깅 프로파일에서만 해당 값을 always 로 설정 → 운영/스테이징에는 노출되지 않음)
+     */
+    private boolean isErrorDetailEnabled() {
+        String includeStacktrace = environment.getProperty("server.error.include-stacktrace", "never");
+        return "always".equalsIgnoreCase(includeStacktrace);
+    }
+
+    private String resolveActiveProfile() {
+        String[] activeProfiles = environment.getActiveProfiles();
+        if (activeProfiles.length == 0) {
+            return "default";
+        }
+        return String.join(", ", activeProfiles);
+    }
+
+    private Throwable resolveThrowable(HttpServletRequest request) {
+        Object exception = request.getAttribute(RequestDispatcher.ERROR_EXCEPTION);
+        if (exception instanceof Throwable) {
+            return (Throwable) exception;
+        }
+        return null;
+    }
+
+    private String stackTraceAsString(Throwable throwable) {
+        StringWriter stringWriter = new StringWriter();
+        throwable.printStackTrace(new PrintWriter(stringWriter));
+        return stringWriter.toString();
+    }
+
     private String resolveTitle(Object status) {
         HttpStatus httpStatus = resolveHttpStatus(status);
         if (httpStatus == null) {
diff --git a/src/main/resources/templates/views/error.html b/src/main/resources/templates/views/error.html
index 5a7d0bd..42fb5a2 100644
--- a/src/main/resources/templates/views/error.html
+++ b/src/main/resources/templates/views/error.html
@@ -150,6 +150,47 @@
             white-space: pre-wrap;
         }
 
+        /* Dev Error Detail (운영 미노출) */
+        .error-detail-wrap {
+            display: flex;
+            flex-direction: column;
+            gap: 14px;
+            width: 100%;
+        }
+
+        .error-dev-notice {
+            background-color: #fffaf0;
+            border: 1px solid #f6e05e;
+            border-radius: 8px;
+            padding: 12px 18px;
+            font-size: 14px;
+            line-height: 1.6;
+            color: #975a16;
+            text-align: left;
+        }
+
+        .error-dev-notice .error-env {
+            display: inline-block;
+            margin-top: 4px;
+        }
+
+        .error-dev-notice .error-env strong {
+            color: #c05621;
+        }
+
+        /* Stack Trace */
+        .error-stacktrace-text {
+            font-family: 'SFMono-Regular', Consolas, 'Liberation Mono', Menlo, monospace;
+            font-size: 12px;
+            color: #742a2a;
+            line-height: 1.5;
+            text-align: left;
+            white-space: pre;
+            overflow: auto;
+            max-height: 360px;
+            margin: 0;
+        }
+
         /* Responsive */
         @media screen and (max-width: 600px) {
             .error-container {
@@ -219,10 +260,29 @@
             잠시 후 다시 시도해 주세요.
         </p>
 
-        <!-- Error Message (서버에서 전달된 에러 메시지가 있을 경우 표시) -->
-        <div th:if="${errorMessage}" class="error-message-box">
-            <p class="error-message-label">오류 상세</p>
-            <p class="error-message-text" th:text="${errorMessage}"></p>
+        <!-- 상세 오류 정보 (개발 환경 전용) - 운영(prod)에서는 표시되지 않음 -->
+        <div th:if="${errorMessage}" class="error-detail-wrap">
+            <!-- 운영 미노출 안내 + 현재 환경 -->
+            <p class="error-dev-notice">
+                ⚠ 아래 상세 정보는 개발 편의를 위한 것으로,
+                <strong>운영 환경에서는 표시되지 않습니다.</strong>
+                <span class="error-env">현재 환경: <strong th:text="${activeProfile} ?: 'default'">-</strong></span>
+            </p>
+
+            <!-- 오류 메시지 -->
+            <div class="error-message-box">
+                <p class="error-message-label">오류 상세</p>
+                <p class="error-message-text" th:text="${errorMessage}"></p>
+            </div>
+
+            <!-- 스택 트레이스 (include-stacktrace=always 이고 예외가 있을 때만) -->
+            <div th:if="${errorStackTrace}" class="error-message-box">
+                <p class="error-message-label">
+                    <span>스택 트레이스</span>
+                    <span th:if="${errorException}" th:text="'(' + ${errorException} + ')'"></span>
+                </p>
+                <pre class="error-stacktrace-text" th:text="${errorStackTrace}"></pre>
+            </div>
         </div>
 
         <!-- Action Buttons -->