diff --git a/.editorconfig b/.editorconfig
new file mode 100644
index 0000000..d740d41
--- /dev/null
+++ b/.editorconfig
@@ -0,0 +1,2 @@
+[*]
+charset = utf-8
diff --git a/CRC.h b/CRC.h
index 4885d48..1aab83b 100644
--- a/CRC.h
+++ b/CRC.h
@@ -1,4 +1,4 @@
-#pragma once
+#pragma once
 #include <cstdint>
 
 // CRC-32
diff --git a/MyZip.vcxproj b/MyZip.vcxproj
index e0ec898..3f48ed7 100644
--- a/MyZip.vcxproj
+++ b/MyZip.vcxproj
@@ -102,6 +102,9 @@
       <SDLCheck>true</SDLCheck>
       <PreprocessorDefinitions>_DEBUG;_CONSOLE;%(PreprocessorDefinitions)</PreprocessorDefinitions>
       <ConformanceMode>true</ConformanceMode>
+      <LanguageStandard>stdcpp20</LanguageStandard>
+      <LanguageStandard_C>stdc17</LanguageStandard_C>
+      <AdditionalOptions>/utf-8 %(AdditionalOptions)</AdditionalOptions>
     </ClCompile>
     <Link>
       <SubSystem>Console</SubSystem>
@@ -116,6 +119,9 @@
       <SDLCheck>true</SDLCheck>
       <PreprocessorDefinitions>NDEBUG;_CONSOLE;%(PreprocessorDefinitions)</PreprocessorDefinitions>
       <ConformanceMode>true</ConformanceMode>
+      <LanguageStandard>stdcpp20</LanguageStandard>
+      <LanguageStandard_C>stdc17</LanguageStandard_C>
+      <AdditionalOptions>/utf-8 %(AdditionalOptions)</AdditionalOptions>
     </ClCompile>
     <Link>
       <SubSystem>Console</SubSystem>
diff --git a/ZipDefine.h b/ZipDefine.h
index ad3d53f..0131731 100644
--- a/ZipDefine.h
+++ b/ZipDefine.h
@@ -1,4 +1,4 @@
-#pragma once
+#pragma once
 
 #include <cstdint>
 
@@ -70,6 +70,9 @@ constexpr int LOCAL_FILE_HEADER_BYTE = 30;
       // var[lengthOfExtraField] extraField
  };
 
+ // 정적 메모리 사이즈 검사
+ static_assert(sizeof(LocalFileHeader) == LOCAL_FILE_HEADER_BYTE, "LocalFileHeader Size is mismatch");
+
 /**   Central directory structure:
 
       [central directory header 1]
@@ -130,6 +133,9 @@ constexpr int LOCAL_FILE_HEADER_BYTE = 30;
       // var[lengthOfFileComment] fileComment
 };
 
+ // 정적 메모리 사이즈 검사
+ static_assert(sizeof(CentralDirectory) == CENTRAL_DIRECTORY_BYTE, "CentralDirectory Size is mismatch");
+
  /**  End of central directory record:
 
       end of central dir signature    4 bytes  (0x0605 + 4b50)
@@ -179,4 +185,7 @@ constexpr int LOCAL_FILE_HEADER_BYTE = 30;
       // var[LengthOfCommentLength] zipFileComment
 };
 
+ // 정적 메모리 사이즈 검사
+ static_assert(sizeof(EoCDRecord) == EOCD_BYTE);
+
 #pragma pack(pop)
diff --git a/main.cpp b/main.cpp
index af0d090..580a9f3 100644
--- a/main.cpp
+++ b/main.cpp
@@ -1,4 +1,4 @@
-#include <cstdio>
+#include <cstdio>
 #include <iostream>
 #include <cstring>
 #include <fstream>
@@ -17,46 +17,25 @@ int main()
 	std::printf("==================== Hello Zip! ====================\r\n");
 	int iRet = 0;
 
-	// Zip Format define check
-	// 생성자를 만들어서, 생성되면서 사이즈 검사?
-
-	size_t iSizeTest = sizeof(LocalFileHeader);
-	if (LOCAL_FILE_HEADER_BYTE != iSizeTest)
-	{
-		std::printf("1 Wrong Header Size : %zu / %d \r\n", iSizeTest, LOCAL_FILE_HEADER_BYTE);
-		iRet = -1;
-	}
-	iSizeTest = sizeof(CentralDirectory);
-	if (CENTRAL_DIRECTORY_BYTE != iSizeTest)
-	{
-		std::printf("2 Wrong Header Size : %zu / %d \r\n", iSizeTest, CENTRAL_DIRECTORY_BYTE);
-		iRet = -1;
-	}
-	iSizeTest = sizeof(EoCDRecord);
-	if (EOCD_BYTE != iSizeTest)
-	{
-		std::printf("3 Wrong Header Size : %zu / %d \r\n", iSizeTest, EOCD_BYTE);
-		iRet = -1;
-	}
-
 	// Main Zip archive method
-	if (iRet != -1)
+	if(!ZipArchiver())
 	{
-		if(!ZipArchiver())
-		{
-			iRet = -1;
-		}
+		iRet = -1;
+		std::printf("[ ERROR ] Somthing went Wrong... \r\n");
+	}
+	else
+	{
+		std::printf("==================== Good Bye Zip! ====================\r\n");
 	}
 
-	std::printf("==================== Good Bye Zip! ====================\r\n");
 	return iRet;
 }
 
 bool ZipArchiver()
 {
-	LocalFileHeader LFHeader = {};
-	CentralDirectory CentDir = {};
-	EoCDRecord EOCDR = {};
+	LocalFileHeader LFHeader{};
+	CentralDirectory CentDir{};
+	EoCDRecord EOCDR{};
 
 	using namespace std;
 
@@ -77,6 +56,7 @@ bool ZipArchiver()
 
 		// TODO : Buffering 으로 구현. 현재는 파일 통짜로 읽음.
 		// 메모리 할당
+		// TODO : 자동으로 free 되는 구조로 변경
 		auto pFile = (char *)malloc(fileInSize);
 
 		// Read
@@ -117,7 +97,7 @@ bool ZipArchiver()
 			CentDir.sizeOfCompressed = CentDir.sizeOfUncompressed;
 
 			// Put File name length
-			uint16_t fileNameLeng = strlen(INPUT_FILE_NAME);
+			uint16_t fileNameLeng = static_cast<uint16_t>(strlen(INPUT_FILE_NAME));
 			LFHeader.lengthOfFileName = fileNameLeng;
 			CentDir.lengthOfFileName = fileNameLeng;
 
@@ -153,8 +133,10 @@ bool ZipArchiver()
 			else
 			{
 				// 1. Local File Header, file name (var), extra field (var)
-				CentDir.offsetLocalFileHeader = fileOut.tellp();
+				CentDir.offsetLocalFileHeader = static_cast<uint32_t>(fileOut.tellp());
 				// TODO : sizeof 의 값이 스펙과 정확히 일치한다는 보장 필요 (현재는 compiler 에 종속적)
+				//		: offsetof((LocalFileHeader, crc32) 으로 멤버별 static_assert 로 변경할 지 고민.
+				//		: 아니면 필드 단위 직접쓰기로 struct 분해하기?
 				fileOut.write(reinterpret_cast<const char*>(&LFHeader), sizeof(LFHeader));
 				fileOut.write(INPUT_FILE_NAME, LFHeader.lengthOfFileName);
 				//fileOut.write(NOT_USED, LFHeader.LFHeader.lengthOfExtraField);
@@ -163,7 +145,7 @@ bool ZipArchiver()
 				fileOut.write(pFile, fileInSize);
 
 				// 3. CentralDirectory, file name (var)
-				EOCDR.offsetCentralDir = fileOut.tellp();
+				EOCDR.offsetCentralDir = static_cast<uint32_t>(fileOut.tellp());
 				// TODO : sizeof 의 값이 스펙과 정확히 일치한다는 보장 필요 (현재는 compiler 에 종속적)
 				fileOut.write(reinterpret_cast<const char*>(&CentDir), sizeof(CentDir));
 				fileOut.write(INPUT_FILE_NAME, CentDir.lengthOfFileName);