To provide a file transfer method capable of improving reliability of file transfer.

In the file transfer method for transferring a file from a transfer source computer 11 to a transfer destination computer 12 by use of a Ftp command, an original file stored in the transfer source computer 1 is transferred to the transfer destination computer 12 with a temporary name. The transfer source computer 11 compares the transferred temporary name file with the original file, changes the name of the temporary file stored in the transfer destination computer 12 to the name of the original file when the content of the temporary name file is matched to that of the original file, and determines whether or not the name of the temporary name file stored in the transfer destination computer is normally changed to the name of the original file.