PURPOSE: To eliminate torque ripples and to reduce loss of a servo motor comprising a motor for controlling the torque and the rotational speed based on a current command and mounting a permanent magnet type holding brake.

CONSTITUTION: In the control method, a current signal Ib corresponding to a holding torque is fed back to the current command Ia of a motor. The control system comprises a multiplier for multiplying the current command Ia of the motor by a factor, a comparator for comparing the motor current command Ia with the current signal corresponding to the holding torque, a controller producing a current signal corresponding to the holding torque, a switch for switching the feedback of the current signal corresponding to the holding torque to the comparator according to the rotational speed, and a comparator 11 for making a decision whether the rotational speed of the rotor is equal to a set value and controlling the function of the switch.