PURPOSE: To automatically adjust optimum position gain and speed gain by providing an inner parameter, which shows the position gain and the speed gain, corresponding to each operation command of a user program, and performing autotuning operation at every finish of each operation.

CONSTITUTION: CPU 31 forms a position control loop and a speed control loop, based on the position of a device being an object of control and the speed detected from the output of the encoder counter 34 provided at a motor 200. To automatically adjust the position gain and the speed gain of this position loop and speed control loop, a user program has an inner parameter, corresponding to each operation command, and the position gain and the speed gain are stored in this inner parameter. Here, the inner parameter corresponding to each operation is updated by performing autotuning operation each time each operation ends, and the object of control is controlled, using the position gain and the speed gain set anew.