To provide an electrostatic actuator, which can obtain sufficient generation power by preventing the drop of the amount of displacement of a diaphragm while suppressing drive voltage, in relatively small constitution, and to provide its manufacturing method, and a drop discharging head and its manufacturing method.

This electrostatic actuator has an electrode 142, a diaphragm 131 which is opposed across a first air-gap G1 to the electrode 142, and a diaphragm 125 which is opposed across a second air-gap G2, on the opposite side from the electrode 142, to the diaphragm 131. Then, this is so constituted as to drive the diaphragm 131 and the diaphragm 125 periodically by applying voltage between the electrode 142 and the diaphragm 131 and between the diaphragm 131 and the diaphragm 125 thereby generating electrostatic attraction between the electrode 142 and the diaphragm 131 and between the diaphragm 131 and the diaphragm 125.