[local file header1] [file data 1] . . . [local file header n] [file data n] [central directory] [end of central directory record]
local file header signature 4 bytes (0x04034b50) version needed to extract 2 bytes (普通は0x000Aかな) general purpose bit flag 2 bytes (普通は0x0000) compression method 2 bytes (普通は0x0000) last mod file time 2 bytes 上位５ビットが時間（２４時間），次６ビットが分，残り５ビットが秒の半分？ last mod file date 2 bytes 下位５ビットが日，その次４ビットが月，残りの上位ビットが年をあらわすみたい 年は1980年が０？ crc-32 4 bytes compressed size 4 bytes uncompressed size 4 bytes file name length 2 bytes extra field length 2 bytes file name (variable size) extra field (variable size)
[file header 1] . . . [file header n] File header: central file header signature 4 bytes (0x02014b50) version made by 2 bytes version needed to extract 2 bytes general purpose bit flag 2 bytes compression method 2 bytes last mod file time 2 bytes last mod file date 2 bytes crc-32 4 bytes compressed size 4 bytes uncompressed size 4 bytes file name length 2 bytes extra field length 2 bytes file comment length 2 bytes disk number start 2 bytes internal file attributes 2 bytes external file attributes 4 bytes relative offset of local header 4 bytes file name (variable size) extra field (variable size) file comment (variable size)
end of central dir signature 4 bytes (0x06054b50) number of this disk 2 bytes number of the disk with the start of the central directory 2 bytes total number of entries in the central directory on this disk 2 bytes total number of entries in the central directory 2 bytes size of the central directory 4 bytes offset of start of central directory with respect to the starting disk number 4 bytes .ZIP file comment length 2 bytes .ZIP file comment (variable size)
参考：http://www.pkware.com/products/enterprise/white_papers/appnote.html