To prevent occurrence of resonance, and also block occurrence of excessive relative displacement, by changing the rigidity of a super magnetostrictive member interposed between an apparatus and a structural body.

A structural body 1 mainly vibrated in a vertical direction supports an apparatus 2 such as an engine, an electric motor and a communication apparatus through supporting parts 3a, 3b comprising a super magnetostrictive member. Coils 4a, 4b are wound around these supporting parts 3a, 3b, and when distortion is generated in the super magnetostrictive member, a circumferential magnetic field is changed and induced electromotive force is generated in the coils 4a, 4b. Namely, when switches 5a, 5b are closed, the magnetic field is generated and the elastic modulus of the supporting parts 3a, 3b is changed. Therefore, if supporting rigidity is enhanced when large acceleration G1 is applied to the structural body 1, the change of the supporting parts 3a, 3b is diminished therefore, the apparatus 2 and the structural body 1 can be prevented from being collided with each other. Also, even though the frequency of the vibration acceleration G1 of the structural body 1 approaches resonance frequency, when the supporting rigidity of the supporting parts 3a, 3b is changed, natural frequency is changed so as to avoid resonance.