A tape drive device including a tape driver for information recording or reproduction is performed on a magnetic tape when a tape cassette having the magnetic tape accommodated therein is loaded, a memory driver through which when a memory for recording management information to manage the recording or reproduction to the magnetic tape is provided to the tape cassette, read-out or writing of the management information from/into the memory can be performed, a detector for detecting storage capacity information of the memory which is stored in the memory, and an identifier for identifying the storage capacity of the memory on the basis of the storage capacity information.