Patent ID: 8537520

Claim:
A method of controlling an electrostatic actuator having a first electrode and a second electrode formed such that they come close to each other when the electrostatic actuator is shifted from an open state to a closed state by electrostatic attraction against elastic force comprising: applying an operation voltage between the first electrode and the second electrode to shift the electrostatic actuator from the open state to the closed state; applying a hold voltage equal to or less than the operation voltage between the first electrode and the second electrode to keep the closed state of the electrostatic actuator; applying a monitor voltage smaller than the hold voltage between the first electrode and the second electrode to determine a trap state of a charge to the first electrode and the second electrode; detecting a capacitance between the first electrode and the second electrode when a voltage between the first electrode and the second electrode is switched from the hold voltage to the monitor voltage; and performing a predetermined operation based on a result of detection of the capacitance.