In a II-VI group semiconductor laser, on an n type GaAs substrate, n type ZnSe layer, a multiquantum well layer of a ZnCdSe well layer and a ZnSe barrier layer, and a p type ZnSe layer are deposited in this order. A polycrystalline ZnO layer is provided on both sides of the p type ZnSe layer for constricting current. Multifilm reflecting mirrors, respectively constituted with a polycrystalline SiO 2 layer and a polycrystalline TiO 2 layer, for obtaining laser oscillation are provided on, the p type ZnSe layer as well as on a surface of the n type ZnSe layer exposed by etching the GaAs substrate. Furthermore, a p type AuPd electrode and an n type AuGeNi electrode are respectively provided. Alternatively, on an n type GaAs substrate, an n type ZnSe epitaxial layer, an n type ZnMgSSe cladding layer, an n type ZnSSe optical waveguide layer, a ZnCdSe active layer, a p type ZnSSe optical waveguide layer, a p type ZnMgSSe cladding layer, a p type ZnTe contact layer and a polycrystalline ZnO burying layer are respectively formed. Furthermore, a p type AuPd electrode and an n type In electrode are respectively provided.