A semiconductor laser device includes: an active layer formed on a
substrate and including an AlGaAs layer; and an upper spacer layer formed
at least one of above and below the active layer and including
Al.sub.aGa.sub.bIn.sub.1-a-bP (where 0.ltoreq.a.ltoreq.1,
0.ltoreq.b.ltoreq.1, and 0.ltoreq.a+b.ltoreq.1). The upper spacer layer
has a composition enough to serve as a barrier layer against electrons
injected into the active layer.