diff --git a/src/api/sseClient.ts b/src/api/sseClient.ts
index 49a339e..b778440 100644
--- a/src/api/sseClient.ts
+++ b/src/api/sseClient.ts
@@ -95,13 +95,28 @@ export const createSSEConnection = <T = unknown>(
         buffer = lines.pop() || "";
 
         for (const line of lines) {
-          if (line.startsWith("data:")) {
-            try {
-              const data = JSON.parse(line.substring(5).trim());
-              onMessage(data);
-            } catch (error) {
-              console.error("Failed to parse SSE data:", error);
+          if (!line.startsWith("data:")) {
+            continue;
+          }
+
+          const payload = line.substring(5).trim();
+          if (!payload) {
+            continue;
+          }
+
+          // 일부 서버는 연결 확인을 위해 단순 문자열을 보낼 수 있으므로 JSON 형태만 처리
+          if (!payload.startsWith("{") && !payload.startsWith("[")) {
+            if (import.meta.env.DEV) {
+              console.debug("Ignoring non-JSON SSE payload:", payload);
             }
+            continue;
+          }
+
+          try {
+            const data = JSON.parse(payload);
+            onMessage(data);
+          } catch (error) {
+            console.error("Failed to parse SSE data:", error, payload);
           }
         }
       }
diff --git a/src/main.tsx b/src/main.tsx
index 4060255..68e66e7 100644
--- a/src/main.tsx
+++ b/src/main.tsx
@@ -6,6 +6,7 @@ import router from "./router";
 import { Toaster } from "react-hot-toast";
 import { QueryClient, QueryClientProvider } from "@tanstack/react-query";
 import { useAuthStore } from "@/domains/login/store/useAuthStore";
+import AlertProvider from "@/shared/providers/AlertProvider";
 
 const queryClient = new QueryClient();
 
@@ -27,13 +28,15 @@ useAuthStore.getState().restoreAuth();
 createRoot(document.getElementById("root")!).render(
   <StrictMode>
     <QueryClientProvider client={queryClient}>
-      <RouterProvider router={router} />
-      <Toaster
-        position="top-right"
-        toastOptions={{
-          duration: 3000,
-        }}
-      />
+      <AlertProvider>
+        <RouterProvider router={router} />
+        <Toaster
+          position="top-right"
+          toastOptions={{
+            duration: 3000,
+          }}
+        />
+      </AlertProvider>
     </QueryClientProvider>
   </StrictMode>
 );
diff --git a/src/shared/hooks/useServerRoomAlerts.ts b/src/shared/hooks/useServerRoomAlerts.ts
index 9c4401a..b8463ff 100644
--- a/src/shared/hooks/useServerRoomAlerts.ts
+++ b/src/shared/hooks/useServerRoomAlerts.ts
@@ -1,6 +1,6 @@
 import { useEffect, useState, useRef, useCallback } from 'react';
-import { createAlertSSE } from '@/api/sseClient';
-import { alertApi, type Alert } from '@/api/alertApi';
+import type { Alert } from '@/api/alertApi';
+import { useAlertStore } from '@/shared/store/useAlertStore';
 
 export interface RackAlert {
   rackId: number;
@@ -8,14 +8,17 @@ export interface RackAlert {
   latestAlert: Alert;
 }
 
+const ALERT_TTL_MS = 5 * 60 * 1000;
+
 /**
  * 서버실 알림을 실시간으로 수신하고 랙별 알림 상태를 관리하는 Hook
  * @param serverRoomId 서버실 ID (없으면 전체 알림 수신)
  */
 export const useServerRoomAlerts = (serverRoomId?: number) => {
   const [rackAlerts, setRackAlerts] = useState<Map<number, RackAlert>>(new Map());
-  const sseConnectionRef = useRef<ReturnType<typeof createAlertSSE> | null>(null);
-  const clearTimersRef = useRef<number[]>([]);
+  const clearTimersRef = useRef<Map<number, number>>(new Map());
+  const processedAlertsRef = useRef<Set<number>>(new Set());
+  const alerts = useAlertStore((state) => state.alerts);
 
   const shouldProcessAlert = useCallback(
     (alert: Alert) => {
@@ -44,6 +47,9 @@ export const useServerRoomAlerts = (serverRoomId?: number) => {
   }, []);
 
   const scheduleAlertCleanup = useCallback((alert: Alert) => {
+    const elapsed = Date.now() - new Date(alert.triggeredAt).getTime();
+    const remaining = Math.max(0, ALERT_TTL_MS - elapsed);
+
     const timeoutId = window.setTimeout(() => {
       setRackAlerts((prev) => {
         const newMap = new Map(prev);
@@ -55,9 +61,15 @@ export const useServerRoomAlerts = (serverRoomId?: number) => {
         }
         return newMap;
       });
-    }, 300000);
+      clearTimersRef.current.delete(alert.alertId);
+      processedAlertsRef.current.delete(alert.alertId);
+    }, remaining);
 
-    clearTimersRef.current.push(timeoutId);
+    const previousTimer = clearTimersRef.current.get(alert.alertId);
+    if (previousTimer) {
+      clearTimeout(previousTimer);
+    }
+    clearTimersRef.current.set(alert.alertId, timeoutId);
   }, []);
 
   const processAlert = useCallback(
@@ -75,59 +87,35 @@ export const useServerRoomAlerts = (serverRoomId?: number) => {
   );
 
   useEffect(() => {
-    let isMounted = true;
-
-    const fetchInitialAlerts = async () => {
-      try {
-        const response = await alertApi.getAlerts({ page: 0, size: 200, days: 1 });
-        if (!isMounted) return;
-
-        const relevantAlerts = response.content.filter(shouldProcessAlert);
-
-        setRackAlerts((prev) => {
-          let newMap = new Map(prev);
-          relevantAlerts.forEach((alert) => {
-            newMap = upsertAlert(newMap, alert);
-            scheduleAlertCleanup(alert);
-          });
-          return newMap;
-        });
-      } catch (error) {
-        console.error('Failed to fetch initial alerts:', error);
-      }
-    };
-
-    fetchInitialAlerts();
+    clearTimersRef.current.forEach((timeoutId) => {
+      clearTimeout(timeoutId);
+    });
+    clearTimersRef.current.clear();
+    processedAlertsRef.current.clear();
+    setRackAlerts(new Map());
+  }, [serverRoomId]);
 
-    // SSE 연결 생성
-    const connection = createAlertSSE<Alert>({
-      onMessage: (alert) => {
+  useEffect(() => {
+    alerts.forEach((alert) => {
+      if (!processedAlertsRef.current.has(alert.alertId) && shouldProcessAlert(alert)) {
+        processedAlertsRef.current.add(alert.alertId);
         processAlert(alert);
-      },
-      onError: (error) => {
-        console.error('Alert SSE error in useServerRoomAlerts:', error);
-      },
-      onOpen: () => {
-        console.log('Alert SSE connection established in useServerRoomAlerts');
-      },
+      }
     });
+  }, [alerts, processAlert, serverRoomId, shouldProcessAlert]);
 
-    sseConnectionRef.current = connection;
+  useEffect(() => {
+    const timers = clearTimersRef.current;
+    const processed = processedAlertsRef.current;
 
-    // 클린업
     return () => {
-      isMounted = false;
-      if (sseConnectionRef.current) {
-        sseConnectionRef.current.close();
-        sseConnectionRef.current = null;
-      }
-
-      clearTimersRef.current.forEach((timeoutId) => {
+      timers.forEach((timeoutId) => {
         clearTimeout(timeoutId);
       });
-      clearTimersRef.current = [];
+      timers.clear();
+      processed.clear();
     };
-  }, [processAlert, scheduleAlertCleanup, shouldProcessAlert, upsertAlert]);
+  }, []);
 
   return { rackAlerts };
 };
diff --git a/src/shared/layout/NotificationBell.tsx b/src/shared/layout/NotificationBell.tsx
index 24744ba..a4bb4f1 100644
--- a/src/shared/layout/NotificationBell.tsx
+++ b/src/shared/layout/NotificationBell.tsx
@@ -1,51 +1,19 @@
-import { useState, useRef, useEffect } from "react";
+import { useState, useRef, useEffect, useMemo } from "react";
 import { useNavigate } from "react-router-dom";
 import { IoNotificationsOutline } from "react-icons/io5";
 import { alertApi, type Alert } from "@/api/alertApi";
-import { createAlertSSE } from "@/api/sseClient";
+import { useAlertStore } from "@/shared/store/useAlertStore";
 
 function NotificationBell() {
   const [isOpen, setIsOpen] = useState(false);
-  const [alerts, setAlerts] = useState<Alert[]>([]);
   const dropdownRef = useRef<HTMLDivElement>(null);
   const navigate = useNavigate();
+  const alerts = useAlertStore((state) => state.alerts);
+  const clearAlerts = useAlertStore((state) => state.clearAlerts);
 
-  const unreadCount = alerts.filter((alert) => !alert.isRead).length;
+  const latestAlerts = useMemo(() => alerts.slice(0, 50), [alerts]);
 
-  // SSE 연결 및 초기 데이터 로드
-  useEffect(() => {
-    // 초기 알림 데이터 가져오기
-    const fetchInitialAlerts = async () => {
-      try {
-        const response = await alertApi.getAlerts({ page: 0, size: 20, days: 7 });
-        setAlerts(response.content);
-      } catch (error) {
-        console.error("Failed to fetch initial alerts:", error);
-      }
-    };
-
-    fetchInitialAlerts();
-
-    // SSE 연결 생성
-    const sseConnection = createAlertSSE<Alert>({
-      onMessage: (newAlert) => {
-        console.log("New alert received:", newAlert);
-        // 새 알림을 맨 앞에 추가
-        setAlerts((prev) => [newAlert, ...prev]);
-      },
-      onError: (error) => {
-        console.error("Alert SSE error:", error);
-      },
-      onOpen: () => {
-        console.log("Alert SSE connection established");
-      },
-    });
-
-    // 컴포넌트 언마운트 시 SSE 연결 종료
-    return () => {
-      sseConnection.close();
-    };
-  }, []);
+  const unreadCount = latestAlerts.filter((alert) => !alert.isRead).length;
 
   // 외부 클릭 감지
   useEffect(() => {
@@ -74,7 +42,7 @@ function NotificationBell() {
   const handleDeleteAll = async () => {
     try {
       await alertApi.deleteAllAlerts();
-      setAlerts([]);
+      clearAlerts();
     } catch (error) {
       console.error("Failed to delete all alerts:", error);
     }
@@ -137,13 +105,13 @@ function NotificationBell() {
         <div className="absolute right-0 mt-2 w-80 bg-black/40 backdrop-blur-sm rounded-lg shadow-xl border border-slate-300/40 z-1000 overflow-hidden">
 
           <div className="max-h-96 overflow-y-auto">
-            {alerts.length === 0 ? (
+            {latestAlerts.length === 0 ? (
               <div className="px-4 py-8 text-center text-gray-400">
                 새로운 알림이 없습니다.
               </div>
             ) : (
               <div className="divide-y divide-gray-700">
-                {alerts.map((alert) => (
+                {latestAlerts.map((alert) => (
                   <div
                     key={alert.alertId}
                     onClick={() => handleAlertClick(alert)}
@@ -180,7 +148,7 @@ function NotificationBell() {
             )}
           </div>
 
-          {alerts.length > 0 && (
+          {latestAlerts.length > 0 && (
             <div className="px-4 py-2 border-t border-gray-700">
               <button 
                 onClick={handleDeleteAll}
diff --git a/src/shared/providers/AlertProvider.tsx b/src/shared/providers/AlertProvider.tsx
new file mode 100644
index 0000000..1c06c64
--- /dev/null
+++ b/src/shared/providers/AlertProvider.tsx
@@ -0,0 +1,39 @@
+import { type PropsWithChildren, useEffect, useRef } from 'react';
+import { createAlertSSE } from '@/api/sseClient';
+import type { Alert } from '@/api/alertApi';
+import { useAlertStore } from '@/shared/store/useAlertStore';
+
+const AlertProvider = ({ children }: PropsWithChildren): JSX.Element => {
+  const addAlert = useAlertStore((state) => state.addAlert);
+  const connectionRef = useRef<ReturnType<typeof createAlertSSE> | null>(null);
+  const addAlertRef = useRef(addAlert);
+
+  useEffect(() => {
+    addAlertRef.current = addAlert;
+  }, [addAlert]);
+
+  useEffect(() => {
+    const connection = createAlertSSE<Alert>({
+      onMessage: (alert) => {
+        addAlertRef.current(alert);
+      },
+      onError: (error) => {
+        console.error('Global Alert SSE error:', error);
+      },
+      onOpen: () => {
+        console.log('Global Alert SSE connection established');
+      },
+    });
+
+    connectionRef.current = connection;
+
+    return () => {
+      connection.close();
+      connectionRef.current = null;
+    };
+  }, []);
+
+  return <>{children}</>;
+};
+
+export default AlertProvider;
diff --git a/src/shared/store/useAlertStore.ts b/src/shared/store/useAlertStore.ts
new file mode 100644
index 0000000..9ab5bb3
--- /dev/null
+++ b/src/shared/store/useAlertStore.ts
@@ -0,0 +1,24 @@
+import { create } from 'zustand';
+import type { Alert } from '@/api/alertApi';
+
+interface AlertStoreState {
+  alerts: Alert[];
+  maxAlerts: number;
+  addAlert: (alert: Alert) => void;
+  clearAlerts: () => void;
+}
+
+export const useAlertStore = create<AlertStoreState>((set) => ({
+  alerts: [],
+  maxAlerts: 200,
+  addAlert: (alert) =>
+    set((state) => {
+      const deduped = state.alerts.filter((existing) => existing.alertId !== alert.alertId);
+      const next = [alert, ...deduped];
+      return {
+        alerts: next.slice(0, state.maxAlerts),
+        maxAlerts: state.maxAlerts,
+      };
+    }),
+  clearAlerts: () => set((state) => ({ alerts: [], maxAlerts: state.maxAlerts })),
+}));