An optical switch 1 has a plane waveguide 2 provided with optical waveguide 3, and an actuator structure 5 including a beamlike member 6 supported in a doubly supported manner on the plane waveguide 2. A mirror 10 for shutting out light passing on the optical waveguide 3 is provided in the central region of the beamlike member 6. Interconnecting members 12 extending in the longitudinal direction of the beamlike member 6 are coupled to the both ends of the beamlike member 6. The interconnecting members 12 preliminarily exert a compressive force on the beamlike member 6 so as to deflect the beamlike member 6 with compression stress in an initial state in which the mirror 10 is located at a position where the mirror allows the light passing on the optical waveguide 3 to pass or at a position where the mirror shuts out the light passing on the optical waveguide 3.