A semiconductor laser device includes a p-InP cladding layer, an active region, a first n-InP cladding layer, a second n-InP cladding layer, and an n-InGaAsP cladding layer with a thickness between 0.05 m and 0.3 m, sandwiched by the first and second n-laP cladding layers and laminated at a position closer to the active region than a position at which optical intensity of a near-field pattern of laser light emitted from the active region becomes substantially zero. The semiconductor laser device exhibits a small reduction in the optical output even when a large current flows, and has a high slope efficiency without changing the near-field pattern a great deal.