PURPOSE: To control the braking of a motor correctly, by a method wherein the rotating speed of the motor before braking is detected by a motor speed detecting means to correct a field braking signal in accordance with the detected signal.

CONSTITUTION: The driving of the rotor 22 of a motor 20 is controlled by a control unit or a microcomputer 10. The rotating speed of the motor 20 is detected by an encoder 28 and a detected signal is supplied to the microcomputer 10. The driving of said motor 20 is effected through a driving circuit 30 and a braking circuit 40. Further, the microcomputer 10 is constituted of a CPU 12, a ROM 14 and a RAM 16. A predetermined time is determined previously so as to apply braking for a long period when the rotating speed of the motor 20 is high. According to this method, the rotating speed of the motor 20 before braking is detected by the braking circuit 40 to correct a field braking signal in accordance with the result of the detection. The rate of braking is corrected to the predetermined rate of braking, therefore, the braking may be controlled correctly.