PURPOSE: To reduce cost and to shorten time for operation while keeping exact origin out precision by abolishing an origin sensor by performing an origin out operation for the S axis part of a scolar type robot by outputting plural command torque values.

CONSTITUTION: When a first command torque 11 is outputted to a torque control loop 400 and a speed monitor 14 detects the collision of a scolar type robot S axis part 100 to a stopper, a second command torque 12 larger than the first command torque 11 is outputted by a torque changeover switch 13. A loop changeover switch 6 is connected to a position A and switched to a positioning control loop 300 at the timing when this command torque 12 is completely transmitted to the S axis part and present speed is turned to zero, and the value of a present position from a present position counter 204 is substituted to a commanded position 1. Then, a fine moving amount opposite to a previous moving direction is continuously added to the target commanded position 1, and a servo motor 101 is rotated. When an origin pulse signal from a pulse encoder 102 is detected, the present value counter 204 is cleared.