When performing numerical control of a rotary table, the moment of inertia and the center of gravity of a control target change because of a placed object fixed onto the rotary table. A rotary table to which a placed object has been fixed serves as a target plant, the actual motion of this is compared with motion calculated by an identification model of the target plant, and a torque command value is corrected. The identification model comprises a term pertaining to angular acceleration and a term pertaining to angle of rotation, and by including the term pertaining to angle of rotation, correction of a torque command corresponding to a change in the center of gravity can be performed.