PURPOSE: To mount a multihead having high tracking accuracy by enlarging the change in length of a piezoelectric element by a lever and shifting the magnetic head.

CONSTITUTION: When a control signal is input to a laminate-type piezoelectric element 106, the piezoelectric element 106 is extended a predetermined distance in a direction P. At this time, levers 105L and 105R holding the element 106 therebetween sway in the opposite directions, i.e., S and Q about the respective fulcrum parts 105Lc and 105Rc. As a result, of the sway, forces (f) and (g) act to the inclined surfaces at end parts of the levers at the side of points of application, respectively, and a pushing force is impressed to a head supporting member 104 in a direction T. An annular elastic member 109 held between a flange part of a fixed screw 108 and a surface of a supporting member 104 where the head is attached is compressed a predetermined amount in a direction of a central axis thereof, whereby the supporting member 104 is shifted along a guide part 108a of the screw 108 in the T direction. Accordingly, the rigidity when the magnetic head is mounted is enhanced and the change of the length of the piezoelectric element becomes convertible to the shifting amount of the head highly accurately via the shift enlarging levers.