PURPOSE: To make always a tape tension constant, by providing a pulse generating means for a rotating body which is rotated together with a take-up reel and converting the cycle of pulses to a voltage and controlling the electric current of a magnet motor by this voltage.

CONSTITUTION: A rotating body 7 whose outside circumferential part is magnetized in a form of a gear is attached to the same shaft as a take-up tape reel 6, and a pulse genertor 10 is provided for this body 7. When a current proportional to the rotation cycle of the rotating body 7 is flowed to a motor 8, the tape tension can be always made constant. Therefore, pulses proportional to the rotation number of the rotating body 7 are generated from the pulse generator 10, and the cycle of pulses is counted at intervals of a certain time by a CPU 11, and the cycle is converted to a change of the pulse width by a D/A converter 12, and this change is converted to a DC voltage by a DC converting circuit 13, and this voltage is used to drive the motor 8 with the current proportional to the rotation cycle. Thus, the tape tension is always constant.