PURPOSE: To attain a stable operation whose control is easy and exact even when a preliminarily estimated dynamic characteristic model to be controlled is erroneous, and the uncertain part of the model to be controlled is large.

CONSTITUTION: A calculating condition setting part 3 confirms a response to be controlled at a control response display part, sets a calculating condition, and applies it to a control parameter arithmetic part 2. The control parameter arithmetic part 2 calculates a control parameter to a multivariable control part 1 based on the calculating condition. The multivariable control part 1 controls plural manipulated variable by using the parameter. Thus, an operator can attain the field adjustment of the multivariable control part 1 by looking at a response waveform so that the response can be a desired response performance. And also, an optimal controller can be realized in a time less than 1/10 times as long as the time required for the adjustment using a conventional CAD.