PROBLEM TO BE SOLVED: To provide a driving method, drive unit and the like of a capacitance type transducer, capable of reducing variation in transmission sound pressures generated by characteristic variation of a capacitance type transducer for use in an ultrasonic transducer.SOLUTION: Provided is a driving method of a capacitance type transducer 1 that includes a device 3 having cells 2, each configured to support a vibrating film 11 in a way that can vibrate including one electrode 10 of a pair of electrodes that are formed at a gap 8 apart from each other. In a mode in which the device 3 receives an acoustic wave, a voltage smaller than a pull-in voltage is applied to the device as a reception bias voltage. In a mode in which the device transmits the acoustic wave, a voltage smaller than the reception bias voltage is applied to the device as the transmission bias voltage.SELECTED DRAWING: Figure 1
