A semiconductor laser device includes an active layer, a pair of guiding layers sandwiching the active layer, and a pair of cladding layers sandwiching the active layer and the pair of guiding layers. The pair of guiding layers are InGaAsP lattice-matched to GaAs. The pair of cladding layers are AlGaAs. The Al composition ratios of the pair of AlGaAs cladding layers are 0.4 or less. The Al composition ratios are set such that the refractive indices of the pair of AlGas cladding layers do not exceed those of the pair of InGaAsP guiding layers.