To construct a piezoelectric actuator driver circuit that gives stable self-excited vibration even in vibrating a vibrator liable to higher-order resonance.

A resistor R to detect current is inserted in a current path for a piezoelectric actuator (a). A signal of a decreased voltage of the resistor R is subjected to positive feedback to an amplifier circuit AMP via a band-pass filter BPF. An output signal of the amplifier circuit AMP is subjected to negative feedback to the amplifier circuit AMP via a band-elimination filter BEF. The band-pass filter BPF allows a signal of a fundamental resonant frequency of a piezoelectric device equipped with the piezoelectric actuator to pass therethrough, while the band-elimination filter BEF blocks the signal of a fundamental resonant frequency. Thus, a loop gain at a higher-order resonant frequency with respect to the fundamental resonant frequency becomes very low and a higher-order resonant mode can be more reliably suppressed.