To perform tuning in consideration of interference in a multi-variable control system, and to shorten tuning time.

A tuning signal as a pulse operation signal is applied to a controlled target for each channel in order to measure its response, and a PID control parameter of a controller is calculated on the basis of the tuning signal and the response so that the response may be close to a response of a reference model. Input/output data are used to determine a control parameter of the controller so that a response of a closed loop may be close to the response of the reference model. VRFT (Virtual Reference Feedback Tuning) is used to calculate the control parameter.