PURPOSE: To reduce or prevent vibration or noise of a supporting member very effectively by controlling operation of a first exciting means and a second exciting means so as to make the vibrational displacement quantity of a vibration body and vibration transmitting force transmitted from the vibration body to a supporting member to be on low level.

CONSTITUTION: A vibrationproof supporting device 12 is constituted to contain a mass body 16. The mass body 16 is positioned between a power unit 10 and a body 14, and arranged displaceably at least in the direction of vibration to be prevented. A first spring means 18 is interposed between the mass body 16 and the power unit 10, and the mass body 16 and the power unit 10 are elastically connected together at least in the direction of vibration to be prevented by the first spring means 18. Meanwhile, a second spring means 22 and a second exciting means 24 are interposed in parallel between the mass body 16 and the body 14, the mass body 16 and the body 14 are elastically connected together in the direction of vibrationproofing, and exciting force is applied in the vibrational direction.