PURPOSE: To realize accurate positioning with a simple structure by deciding a braking amount of a brake according to a signal in accordance with a sliding mode method by a fuzzy inference, and controlling ON.OFF a second switch in response to the braking amount.

CONSTITUTION: An AC motor 1 is connected to an AC power source 3 through a first switch 2, a brake 5 is coupled to this shaft 4, and a current of a coil 9 of an electromagnet 6 is controlled ON.OFF. The coil 9 of the electromagnet 6 is connected to a DC power source 11 through a second switch 10. A position detector 16 detects an angle position of a rotor of the motor 1 to know a position of a moving element 17, and a counter 18 generates a deviation with data from a target position data generator 19. A fuzzy controller 27 is connected between an output terminal of an arithmetic circuit 22 and one input terminal of a voltage comparator 25 to decide a braking amount of the brake 5.