A fluid sealed vibration insulating device is provided with an actuator 10 for generating an active supporting force. The device includes a main fluid chamber 15 defined by a cylindrical elastic support 6 and a movable plate 12 connected to a non-linear type plate spring 11. The main chamber 15 is communicated with a variable-volume auxiliary chamber 16 through an orifice 5a. The actuator 10 moves the plate 12 to change a dynamic spring characteristic and a damping characteristic of the fluid resonance system constituted by the mass of fluid in the orifice 5a and the expanding direction spring of the elastic support 6 and the plate spring 11. <IMAGE>
