PURPOSE: To provide the actuator for the recording and reproducing device which can suppress the disturbance in a high-frequency region, does not affect the floating behavior of a head at all and has high performance and high reliability and the recording and reproducing device constituted by using this actuator.

CONSTITUTION: Both ends of sheets 3a, 3b are provided with bent parts 5a, 5b, 6a, 6b for connecting either one end of piezoelectric elements 4a, 4b on diagonal lines. The respective ends of the piezoelectric elements 4a, 4b are connected thereto, by which one set of the sheets 3a, 3b and the piezoelectric elements 4a, 4b are integrated and a thin type fine adjustment mechanism part 2 is constituted. The one sheet 3a is fixed to a suspension 14 and the other sheet 3b is fixed to a slider 1 so that the slider 1 can be finely displaced relative to the suspension 14 by driving the respective piezoelectric elements 4a, 4b.