In positioning control of a machine in which residual vibrations are caused due to a low mechanical rigidity, residual vibrations are suppressed within an allowable positioning error, and a positioning time period required for the positioning control is shortened.Based on information of operation conditions and residual vibrations, the amplitude of the residual vibrations of the machine is predicted before execution of positioning, and based on a result of the prediction, a first servo controller (11) which performs positioning control in which suppression of residual vibrations of the machine is not considered or a second servo controller (12) in which suppression of residual vibrations of the machine is considered is automatically selectively used.