A drive unit includes a control unit for controlling an ultrasonic actuator. The control unit performs switching between a normal operation mode in which the piezoelectric element unit vibrates at a frequency close to a resonance frequency of longitudinal vibration in the lengthwise direction of the piezoelectric element unit and a resonance frequency of bending vibration to let the ultrasonic actuator output a driving force and a heating mode in which the piezoelectric element unit vibrates at a frequency close to a resonance frequency of longitudinal vibration in the thickness direction of the piezoelectric element unit to heat the piezoelectric element.