A planar waveguide-type optical amplifier switch is disclosed. The switch is developed with the purpose of solving the problems that the conventional waveguide-type optical switch, which has been being used in the optical communication technique, has an optical loss and thereby requires an external optical amplifier which makes the whole devices not suitable for forming an integrated compact device. The disclosed switch performs switching function from the refractive index change in the optical waveguides induced by electrical or optical controls as well as amplifying function of the optical signal, when it passes through the waveguides, from use of optical waveguides formed of a fluorescence emitting material with an optical pumping and a wavelength division multiplexing (WDM) optical waveguide-type coupler. The optical amplifier switch scheme, which provides a simultaneous optical switching and amplification in an optical waveguide form, allows the device fabricable in a compact integrated manner and more useful in practical applications. The optical amplifier switch in accordance with the present invention can replace the conventional optical switches of the prior art, and can promote technical development in the areas of high-capacity optical communication systems, massive optical signal processing, optical switching, optical computing, and so on.