PURPOSE: To bring a pumping action into full play as a volumetric variation in each fluid chamber is not impeded, by isolating a pressure receiving chamber into a first pressure chamber at the side nearer to an inner cylinder in the vibration inputting direction and a second pressure chamber nearer to an outer cylinder with a rubber elastic partition wall having fair thickness and continuing to both the rubber elastic side walls.

CONSTITUTION: A pressure receiving chamber 20 is partitioned off into a first pressure chamber 20a and a second pressure chamber 20b by a rubber elastic partition wall 30 which has fair thickness. Therefore, in time of vibration, this partition wall 30 alone is complicatedly deformed, absorbing a pressure rise in each of these pressure chambers 20a and 20b, and thus their volumetric variations are not impeded at all. Moreover, this partition wall 30 is installed in succession to both rubber elastic side walls 14. Accordingly, in time of a pressure rise, this side wall 14 is preventable from expanding to the outside. In cooporation with these structures, at the time of vibrations, each capacity of these pressure chambers 20a and 20b is varied to the maximum, bringing a pumping action into full play.