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 capable of easily and surely preventing that the unnecessary material files are accumulated in the storage unit is provided. When the scenario file recorded in a hard disk is deleted, the unnecessary material files in this hard disk are automatically deleted. Namely, in the hard disk, the scenario file to be deleted and the scenario file to be remained are compared with each other, and the material files which are used in the scenario file to be deleted and from which the material files used in the remaining scenario file are excluded are deleted.