PURPOSE: To decrease frequency of overrun by storing a read data in a data buffer when next block is read before a read instruction from a host device reaches and using a read instruction reaches with a delay so as to send a data in the buffer to the host device.

CONSTITUTION: When a read instruction from a host device through a command bus 6 is sent to a command analysis circuit 7, the circuit 7 sends a tape running signal 13 to a tape positioning control circuit 9, which activates a reel drive motor 11 via a servo amplifier 10. Further, a data read by a read head 4 is sent to a data buffer 2 via an amplifier 10, the circuit 7 analyzes the read instruction and sends the data send signal 12 to the buffer 2 and sends the output signal to the host device via a data bus 1. Thus, the data read by the head 4 is stored in the buffer 2 and the data is sent when the read instruction is given from the host device.