A piezoelectric element expands and contracts when a pulse voltage is applied. A fixing body is fixed to one end of the piezoelectric element in an expansion-contraction direction. A driving shaft is fixed to the other end of the piezoelectric element in the expansion-contraction direction. A movable body is supported to the driving shaft slidably. When a pulse voltage is applied to the piezoelectric element, the piezoelectric element contracts and expands. Accordingly, the driving shaft oscillates, and the movable body slides along the driving shaft. A material of the driving shaft is fiber reinforced resin complex. A synthetic resin material composing the fiber reinforced resin complex is liquid crystal polymer or polyphenylene sulfide.