An electrostatic actuator is disclosed that includes a deformable
oscillating plate that is deformed by electrostatic force, an electrode
that is arranged opposite the oscillating plate via a gap formed by
sacrificial layer etching, a connection path that is connected to the
gap, an atmosphere connecting hole that connects the connection path to
the exterior, and a resistance path arranged between the atmosphere
connecting hole and the connection path. The resistance path is
configured to resist penetration of a sealing agent for sealing the
atmosphere connecting hole into the connection path.