Abstract: The backup/restore method as described in this invention has a “backup copy generating process” to generate backup copy(ies) and a “restore process” to restore the original file(s) from the backup copy(ies) generated by the “backup copy generating process,” and includes a process to instruct the execution of the “restore process” by designating the file (name) and the time period backing from the current time (S801-S803), and when the execution of “restore process” is instructed, a process to control the execution of the “restore process” (S804) by selecting the corresponding backup copy file(s), according to the designated file (name) and designated time period.