The semiconductor laser device includes first and second light emitting portions each including a first cladding layer, an active layer and a second cladding layer, and each having a stripe structure. The stripe structure of the first light emitting portion has a section having a width changing along a resonator direction and includes a first front end face, and relationships of W.sub.f1.gtoreq.W.sub.1; W.sub.1>W.sub.2; and (W.sub.f1-W.sub.1)/2L.sub.1<(W.sub.1-W.sub.2)/2L.sub.2 hold wherein W.sub.f1 is a width on the first front end face; W.sub.1 is a width in a position away from the first front end face by a distance L.sub.1; and W.sub.2 is a width in a position away from said the front end face by a distance L.sub.1+L.sub.2 (whereas L.sub.1+L.sub.2.ltoreq.L). The stripe structure of the second first light emitting portion has a section having a width changing along a resonator direction and includes a second front end face, and relationships of W.sub.f2.gtoreq.W.sub.3; W.sub.3>W.sub.4; and (W.sub.f2-W.sub.3)/2L.sub.3<(W.sub.3-W.sub.4)/2L.sub.4 hold wherein W.sub.f2 is a width on the second front end face; W.sub.1 is a width in a position away from the second front end face by a distance L.sub.3 (whereas L.sub.1.noteq.L.sub.3); and W.sub.4 is a width in a position away from the second front end face by a distance L.sub.3+L.sub.4.