PURPOSE: To shorten the time and to save the labor required for production of a file desired by a developer by controlling correctly a file format stored in a constitution format storage means and a file format stored in a file format storage at all times.

CONSTITUTION: The constitution format storage means 101 of an information processing system 100 stores an information group indicating the hierarchical structure of a file system consisting of plural files as a constitution. The file format storage means 102 stores an information group showing the attribute of each file forming a file system as a file format. A command generating means 103 produces each command necessary for the production of an object file by reference to the constitution format stored in the means 101 and the file format stored in the means 102 when the means 103 receives an instruction for the production of a desired file corresponding to the file system. A command execution means 104 executes each command produced by the means 103 and creates the object file.