To secure an asymptotic convergent property of an output error, and accurately exhibit desired force by a hydraulic actuator by controlling force of the hydraulic actuator after a dynamic characteristic of the hydraulic actuator in an active suspension system for a vehicle is changed to low order by using singular perturbation technique.

A data sensor part 22 to sense swinging data is arranged in a car body and a wheel 20 containing a tire, and obtained data is inputted to an active suspension control part 16. Here, force to be exhibited by a hydraulic actuator 14 is calculated to restrain swinging of the car body 20, and a dynamic characteristic of the hydraulic actuator 14 is changed to low order. That is, force to be exhibited by the hydraulic actuator 14 is calculated by a damping control part 160, and then, the dynamic characteristic of the hydraulic actuator 14 is changed to low order by receiving a displacement measured value of a spool valve of the hydraulic actuator 14 by an oil pressure control part 162, and is controlled so that the force calculated by the control part 160 is accurately exhibited by the hydraulic actuator 14.