[EDIT]ヘッダーの読み込みコードを追加しました

src/main/resources/templates/analysis.html

@@ -1,12 +1,15 @@
 <!DOCTYPE html>
 <html xmlns:th="http://www.thymeleaf.org">
 <head>
-<meta content="text/html; charset=UTF-8" http-equiv="Content-Type">
+<meta name="viewport" content="width=device-width, initial-scale=1" http-equiv="Content-Type">
 <title>分析画面</title>
 <link href="https://cdn.jsdelivr.net/npm/bootstrap@5.3.7/dist/css/bootstrap.min.css" rel="stylesheet">
 </head>
 <body>
 	
+	<div th:replace="~{header :: header}">
+	</div>
+	
 	<h2 class="text-center">支出分析</h2>
 	
 	<table class="table text-center">

src/main/resources/templates/header.html

@@ -0,0 +1,29 @@
+<!DOCTYPE html>
+<html xmlns:th="http://www.thymeleaf.org">
+<head>
+<meta charset="UTF-8" name="viewport" content="width=device-width, initial-scale=1">
+<title>ヘッダー</title>
+<link href="https://cdn.jsdelivr.net/npm/bootstrap@5.3.7/dist/css/bootstrap.min.css" rel="stylesheet">
+</head>
+<body>
+	
+	<header th:fragment="header">
+
+		<nav class="navbar" style="background-color: #e3f2fd;" data-bs-theme="light">
+		  <div class="container-fluid">
+		    <a th:href="@{/menu}" class="navbar-brand fw-bold">Monegement</a>
+			<div class="d-flex gap-2">
+				<a class="btn btn-outline-primary btn-sm" th:href="@{/course}">
+					コース
+				</a>
+				<a class="btn btn-outline-secondary btn-sm" th:href="@{/profile}">
+					プロフィール
+				</a>
+			</div>
+		  </div>
+		</nav>
+
+	</header>
+	<script src="https://cdn.jsdelivr.net/npm/bootstrap@5.3.7/dist/js/bootstrap.bundle.min.js"></script>
+</body>
+</html>