To stabilize the utmost positioning performance by specifying the mass of a stage, a viscosity friction coefficient, a spring constant, the primary delay time constant of a power amplifier, a position gain, the gain of the power amplifier, a thrust constant, a numeric value regulating quick response and the coefficient of a reference model in a stage position control system.

In the stage position control system being a PID compensator, the mass of a stage, a viscosity friction coefficient, a spring constant, and the primary delay time constant of a power amplifier driving the stage are set to be m1, b1, k1 and Td. Then, Fi, Fx and Fv are decided, based on respective expressions by setting Kp as a position gain, Ki as the gain of the power amplifier, Kt as a thrust constant, σ as a numeric value regulating quick response which a designer designates and α0, α1, α2 and α3 as the coefficients of a reference model as a desirable response. Thus, the utmost positioning performance can stably be acquired.