In a system for recording scenario and material files into a storage unit and reproducing the material files based on the scenario file, an information processing method easily and surely prevents unnecessary material files from accumulating in the storage unit by, when a scenario file recorded in a hard disk is deleted, unnecessary material files in this hard disk are automatically deleted. Namely, in the hard disk, the scenario file to be deleted and a scenario file to remain are compared with each other, and material files that are used by the scenario file to be deleted and not used by the remaining scenario file are deleted.