Abstract: A semiconductor laser device including the following: a first conductivity type semiconductor substrate; a first conductivity type cladding layer disposed on the semiconductor substrate; an active layer disposed on the first conductivity type cladding layer; a second conductivity type first cladding layer disposed on the active layer; a second conductivity type second cladding layer that is disposed on the second conductivity type first cladding layer and forms a ridge waveguide extending in a resonator direction; a second conductivity type contact layer disposed on the second conductivity type second cladding layer; and an end face window structure in which impurities are diffused into an active layer region of an end face portion in the resonator direction. Thus a band gap is enlarged compared to a gain region that is a portion other than the end face portion.