According to one embodiment, a method of driving an electrostatic actuator includes a first electrode provided on a substrate, a second electrode arranged above the first electrode to be movable in a vertical direction, and an insulating film provided between the first electrode and the second electrode, includes boosting a power supply voltage to generate a driving voltage of the electrostatic actuator, and applying the driving voltage to each of the first electrode and the second electrode when setting the electrostatic actuator in an up state.