A drive unit includes a vibration actuator for controlling the piezoelectric element. A control section controls the vibration actuator switchably between a normal operation mode in which the piezoelectric element vibrates at a predetermined frequency to let the vibration actuator output a driving force, and a heating mode in which the piezoelectric element vibrates in a direction perpendicular to a direction of the driving force at a frequency different from the frequency in the normal operation mode to heat the piezoelectric element.