PURPOSE: To enable a piezoelectric element actuator to be positioned at high precision, by containing positioning data for compensating a positioning error characteristic of a piezoelectric element, and by applying voltage to the piezoelectric actuator at a proper time according to the positioning data.

CONSTITUTION: A command signal necessary for actual positioning is applied to a driving amplifier 3. The displacement degree of a piezoelectric element actuator 2 due to the driving signal of output generated to the piezoelectric element actuator 2 from the driving amplifier 3 is measured by a displacement detector 10. The displacement degree from the reference position of the piezoelectric element actuator 2 which is measured by the displacement detector 10, namely, displacement detection signal showing position deviation is put together with signal from an external section, and the signals put together are stored in a storage circuit 7, as positioning data. According to output from a selection circuit 6, the output of the positioning data is generated from the storage circuit 7 to the driving amplifier 3.