A semiconductor laser device having a lower cladding layer, an active
layer and an upper first cladding layer stacked on a compound
semiconductor substrate in this order, a ridge-shaped upper second
cladding layer provided on the upper first cladding layer, a current
blocking layer provided on both sides of the upper second cladding layer,
and a contact layer provided on the upper second cladding layer. A
current interrupting layer or layers formed of an insulating material are
provided between the upper second cladding layer and the contact layer,
in the vicinity of at least one of a laser emission end face and a
reflective end face, which are both end faces of the device in the
longitudinal direction of the upper second cladding layer.