In a semiconductor laser device having an oscillation wavelength of larger than 760 nm and smaller than 800 nm, on an n-type GaAs substrate (101), there are stacked in sequence an n-type first and second lower cladding layers (103, 104), a lower guide layer (106), a strained InGaAsP multiquantum well active layer (107), an upper guide layer (109), and a p-type upper cladding layer (110). Since the lower guide layer (106) is formed of InGaP, leakage of carriers from an active region is reduced. Also, since the upper guide layer (109) is formed of AlGaAs, an overflow of carriers (electrons in particular) is suppressed.