The demand for small floppy disks has increased in preparation for the coming age of office automation and home automation. To meet this demand, a new 3-inch ″Compact Floppy Disk″ (CFD) which is small and easy to handle has been developed and standardized. This CFD has the same recording capacity as that of conventional 5. 25-inch Mini Floppy Disks (MFD) widely used as external memories for office computers and personal computers, and has a recording format compatible with the MFD. Moreover, this CFD consists of a high-recording-density magnetic sheet in a hard case with a head window shutter capable of automatically opening and closing. The drive system which uses this CFD is 1/4 smaller than conventional MFDs. For these reasons, the CFD is expected to be widely used in many fields in the future.