An optical device comprises a vibration member 20 provided on a substrate 36 transmitting light so as to vibrate said substrate, a driving circuit 29 for driving said vibration member so as to generate nodes of vibration 99 on said substrate, a plurality of electrodes 42, at least one part thereof provided at neighbor of said nodes of vibration which transmits light, and an output circuit 28 to output voltage to said plurality of electrode so as to change an electric field of a surface of said substrate.