To provide a vibration isolator with a new structure, capable of achieving effective vibration isolating effects on minute amplitude vibration.

This vibration isolator 10 using an electrostrictive polymer actuator comprises a vibration isolating mount main body 12 constituted by using the electrostrictive polymer actuator having a laminated structure of an electrostrictive polymer film 20 and electrodes 22a, 22b; a feeder circuit 18 provided with a coil element 14 and connected with the electrodes 22a, 22b of the vibration isolating mount main body 12 to constitute an RLC resonance circuit using the vibration isolating mount main body 12 as a capacitor element; and a vibration isolating control means 16 which generates a vibration isolating basic signal with a frequency corresponding to vibration to be isolated, applies the vibration isolating basic signal to the feeder circuit 18, and impresses AC voltage for drive on the electrodes 22a, 22b of the vibration isolating mount main body 12 by using resonance action of the feeder circuit 18.