PURPOSE: To enable compatibility of a passive method and an active method by having fluid chambers on both sides of a piston of a fluid pressure cylinder communicated to each other through a valve and by connecting a means for supplying fluid to the fluid chambers in parallel with it.

CONSTITUTION: A movable measure 1 is supported by a construction 2 through a spring 3 and a hydraulic cylinder 4, and an orifice 10 and an electromagnetic type valve 11 are provided in an oil chamber 8 and an oil chamber 9 divided by a piston 5 of the hydraulic cylinder 4. A hydraulic pump 12 and a servo valve 15 of a fluid supplying means are provided in these oil chambers 8 and 9. Thus, working fluid generates a damping force through flow resistance of the orifice 10 accompanying a telescopic motion of the hydraulic cylinder 4, that is, vibration restraint in a passive method is generated. In the meantime, when displacement speed exceeds a set value, a controller 16 closes the valve 11, and the hydraulic cylinder 4 is telescopically moved by hydraulic pressure supplied from the hydraulic pump 12, that is, restraint in an active method is generated. Thus, energy can be saved with maintaining a preferable damping function as necessity requires.