In a power steering apparatus employing an EPS (electrical power steering) motor coupled to a steering mechanism, when vibration of the steering mechanism is produced by twisting of tire rubber due to changes in steering angle, resultant pulsation of the drive current of the EPS motor are suppressed by adding to the drive current a current that is of equal frequency and opposite phase to the pulsation. Vibration of the EPS motor shaft, and resultant vibration of the steering wheel and vehicle body, are thereby effectively suppressed.