1. An operation object display limiting method for a file management system performed by a computer, said file management system allowing at least one file and/or one directory to belong to two or more directories, wherein a file or directory specified by an operator of said computer or a program running on said computer as an object to be operated has all directories on its directory path as parent directories by means of extracting the directory path as the directory string between a root directory and the object from a parameter which is given by the operator or program; and a difference in the order in which the directories are listed in a directory string which consists of the parent directories does not affect the directories or files to be operated, and finding the object or the directory whose parent directories include all directories making said directory path but not necessarily requiring the parent-child relationship between said directories except for the object to be operated, said operation object display limiting method comprising: a first step of determining whether there is a parent-child relationship between a file and a directory to be operated in a working directory; and, if it is determined at said first step that there is a parent-child relationship between the file and the directory, selecting the parent directory as an object to be displayed and excluding the child file of the parent directory from display.