PURPOSE: To make it unnecessary to remember all the forms of files to constitute data so that the burden of a user can be lightened.

CONSTITUTION: The form information of the file to constitute the data stored in a data form information storage part 3 is analyzed by a data form information analyzing part 2, and the list of the names of the files corresponding to the form of the file to be a representative is displayed by a file selection list display part 4 on the basis of this analyzed result. The user selects the file corresponding to the data desired to extract, and other file names to constitute the data are generated by a file information generating part 5 on the basis of the selected file and data form information, and are outputted by a file information output part 6.