An information recording apparatus includes recording means for recording a file and filesystem information on a recording medium; filesystem-information generating means for generating the filesystem information for every application software program using the file; and operation control means for controlling the operation of the recording means so as to allocate the filesystem information, generated for every application software program using the file by the filesystem-information generating means, to virtual addresses as one file. When the file is to be recorded by the recording means, the operation control means controls the recording means so as to update the filesystem information corresponding to the application software program using the file to be recorded and to record the updated filesystem information on the recording medium.