PURPOSE: To prevent a magnetic tape from damage in the fast forwarding/ unwinding operation even when a failure is generated in a motor servo circuit, by stopping the supply of a rotation driving signal to be supplied to a reel motor, in the case a command specifying the tape speed becomes a specified speed specification.

CONSTITUTION: In the magnetic tape, the maximum unwinding amount or fast forwarding amount of which is settled, the final controlled rotating speed of the reel 4 at the time when whole tape unwinding is finished becomes a specific rotating speed. So, when the command specifying the tape speed such as becoming lower than the specified speed is supplied to the motor servo circuit 8, the circuit 8 is decided as abnormal by a microcomputer 6a. With this result, a motor driver 9 is controlled by the microcomputer 6a so that the supply of rotation driving signal to be supplied to the reel motor 2 is stopped. Consequently, even if a runaway of the motor 2 is happened due to the abnormality generated on the circuit 8, the motor 2 is forcibly stopped, thereby the magnetic tape is never damaged.