One embodiment provides a piezoelectric vibrator driving circuit for driving a piezoelectric vibrator, the piezoelectric vibrator having an equivalent circuit in which an LC series resonance circuit, an equivalent resistor Rx connected in series thereto and a damping capacitor Co connected in parallel to them are provided, the driving circuit is configured: to detect a driving current Iz flowing through the entire piezoelectric vibrator; to detect a damping current Iy flowing through the damping capacitor Co; to calculate a series resonance current Ix flowing through the LC series resonance circuit by subtracting the detected damping current Iy from the detected driving current Iz; and to perform a phase adjustment so that a phase difference between the calculated series resonance current Ix and a driving voltage Ve to be applied to the piezoelectric vibrator becomes approximately 0.