diff --git a/StringCheck/src/day3/StringCheck.java b/StringCheck/src/day3/StringCheck.java
new file mode 100644
index 0000000..854cdb2
--- /dev/null
+++ b/StringCheck/src/day3/StringCheck.java
@@ -0,0 +1,55 @@
+package day3;
+
+import java.util.Scanner;
+
+
+public class StringCheck {
+    public static void main(String[] args) {
+        
+        String[] messages = {
+                "いまなにしてる？",
+                "何も入力されていません",
+                "投稿文が長すぎます",
+                "↓↓↓↓↓↓　投稿されました　↓↓↓↓↓↓"
+        };
+
+       
+        
+        String str = "";
+
+       
+        while (true) {
+            System.out.println(messages[0]);
+
+                       
+            str = imputString();
+            
+            boolean isEmpty = (str.length() == 0);
+            boolean isTooLong = (str.length() > 140);
+
+           
+            if (isEmpty) {
+                System.out.println(messages[1]);
+                continue;
+            }
+
+            if (isTooLong) {
+                System.out.println(messages[2]);
+                continue;
+            }
+            
+            break;
+        }
+
+        System.out.println();
+        System.out.println(messages[3]);
+        System.out.println(str);
+    }
+    
+    public static String imputString() {
+    	Scanner scanner = new Scanner(System.in);
+    	String line = scanner.nextLine();
+    	return line.strip();
+	}
+}
+