An optical switch is arranged to have so simple a structure that the switch may be reduced in size. The optical switch includes an input waveguide for accepting an optical signal inputted from the outside, a plurality of output waveguides for outputting the optical signals to the outside, a collimate lens for collimating the optical signal passed through the input waveguide, an optical deflector element for switching the propagating direction of the collimated optical signal, a common waveguide through which the optical signal passed through the optical deflector element is propagated, and a light-condensing portion having a plurality of light-condensing lenses integrally formed therein, each of those lenses serving to image the optical signal inputted from the optical deflector element through the common waveguide onto each output waveguide.