diff --git a/SPMS.API/Middlewares/ExceptionMiddleware.cs b/SPMS.API/Middlewares/ExceptionMiddleware.cs
new file mode 100644
index 0000000..297db4c
--- /dev/null
+++ b/SPMS.API/Middlewares/ExceptionMiddleware.cs
@@ -0,0 +1,50 @@
+using SPMS.Domain.Common;
+using SPMS.Domain.Exceptions;
+
+namespace SPMS.API.Middlewares;
+
+public class ExceptionMiddleware
+{
+    private readonly RequestDelegate _next;
+    private readonly ILogger<ExceptionMiddleware> _logger;
+
+    public ExceptionMiddleware(RequestDelegate next, ILogger<ExceptionMiddleware> logger)
+    {
+        _next = next;
+        _logger = logger;
+    }
+
+    public async Task InvokeAsync(HttpContext context)
+    {
+        try
+        {
+            await _next(context);
+        }
+        catch (SpmsException ex)
+        {
+            _logger.LogWarning(ex, "Business exception: {ErrorCode} {Message}", ex.ErrorCode, ex.Message);
+            await HandleSpmsExceptionAsync(context, ex);
+        }
+        catch (Exception ex)
+        {
+            _logger.LogError(ex, "Unhandled exception: {Message}", ex.Message);
+            await HandleUnknownExceptionAsync(context, ex);
+        }
+    }
+
+    private static async Task HandleSpmsExceptionAsync(HttpContext context, SpmsException exception)
+    {
+        context.Response.StatusCode = exception.HttpStatusCode;
+        context.Response.ContentType = "application/json";
+        var response = ApiResponse.Fail(exception.ErrorCode, exception.Message);
+        await context.Response.WriteAsJsonAsync(response);
+    }
+
+    private static async Task HandleUnknownExceptionAsync(HttpContext context, Exception exception)
+    {
+        context.Response.StatusCode = 500;
+        context.Response.ContentType = "application/json";
+        var response = ApiResponse.Fail(ErrorCodes.InternalError, "서버 내부 오류가 발생했습니다.");
+        await context.Response.WriteAsJsonAsync(response);
+    }
+}
diff --git a/SPMS.API/Program.cs b/SPMS.API/Program.cs
index 49e38cc..81da982 100644
--- a/SPMS.API/Program.cs
+++ b/SPMS.API/Program.cs
@@ -1,10 +1,11 @@
 using Microsoft.EntityFrameworkCore;
+using SPMS.API.Middlewares;
 using SPMS.Infrastructure;
 
 
 var builder = WebApplication.CreateBuilder(new WebApplicationOptions
 {
-    WebRootPath = Environment.GetEnvironmentVariable("ASPNETCORE_WEBROOT") 
+    WebRootPath = Environment.GetEnvironmentVariable("ASPNETCORE_WEBROOT")
                   ?? "wwwroot"
 });
 
@@ -19,6 +20,9 @@ builder.Services.AddDbContext<AppDbContext>(options =>
 
 var app = builder.Build();
 
+// ── 1. 예외 처리 (최외곽 — 이후 모든 미들웨어 예외 포착) ──
+app.UseMiddleware<ExceptionMiddleware>();
+
 // Configure the HTTP request pipeline.
 if (app.Environment.IsDevelopment())
 {
@@ -40,7 +44,7 @@ app.UseHttpsRedirection();
 app.UseRouting();
 
 // [4] 요청 처리
-app.MapControllers(); 
+app.MapControllers();
 app.MapFallbackToFile("index.html");
 
 app.Run();
\ No newline at end of file
diff --git a/SPMS.Domain/Exceptions/SpmsException.cs b/SPMS.Domain/Exceptions/SpmsException.cs
new file mode 100644
index 0000000..23ae4b0
--- /dev/null
+++ b/SPMS.Domain/Exceptions/SpmsException.cs
@@ -0,0 +1,33 @@
+using SPMS.Domain.Common;
+
+namespace SPMS.Domain.Exceptions;
+
+public class SpmsException : Exception
+{
+    public string ErrorCode { get; }
+    public int HttpStatusCode { get; }
+
+    public SpmsException(string errorCode, string message, int httpStatusCode = 400)
+        : base(message)
+    {
+        ErrorCode = errorCode;
+        HttpStatusCode = httpStatusCode;
+    }
+
+    // === 팩토리 메서드 ===
+
+    public static SpmsException BadRequest(string message)
+        => new(ErrorCodes.BadRequest, message, 400);
+
+    public static SpmsException Unauthorized(string message)
+        => new(ErrorCodes.Unauthorized, message, 401);
+
+    public static SpmsException NotFound(string message)
+        => new(ErrorCodes.NotFound, message, 404);
+
+    public static SpmsException Conflict(string message)
+        => new(ErrorCodes.Conflict, message, 409);
+
+    public static SpmsException LimitExceeded(string message)
+        => new(ErrorCodes.LimitExceeded, message, 429);
+}