PURPOSE: To dampen micro-vibration, vibration in the case where the number of oscillation changes, with a static displacement permitted.

CONSTITUTION: This vibration control device is provided with a easing 2 which is connected to a fixed system 9 as necessary, and has a roughly-sealed compartment chamber 1 in it, an ER fluid 3 with which the compartment chamber 1 is filled, and where viscosity changes in proportion to voltage, and a rod 4 which passes through the compartment chamber 1 and is inserted in the casing 2 so as to slide, and whose one end side is installed to piping 7. Moreover, this oscillating device is also provided with electrode plates 5 which are mounted in parallel with a narrow clearance S and where voltage is applied to the ER fluid, a piston 6 which is installed to either of the rod 4 or the easing 2 and makes an ER fluid 3 flow in the compartment chamber 1 with the above sliding, and a voltage control means 8 which detects the vibration of piping 7 and changes the voltage of the electrode plates 5 to dampen vibration based on the detected value.