<p>A bimorph element (104) is formed by bonding first and second piezoelectric bodies (101, 102) together with an elastic shim (103) interposed between. The bimorph element (104) is firmly held by a base frame (105) which has a recess and a groove at the bottom of the recess. The elastic shim 103 has an extending portion (103a) which is firmly inserted in the groove and its end portion is inserted in the recess of the base frame (105). A space between the recess and the end portion of the bimorph element is filled by an elastic support member (108). <IMAGE></p>