A semiconductor laser device includes an n-type clad layer, an active layer, and a p-type clad layer having a ridge and wing regions. The wing regions are provided with a first trench present on one side of the ridge and a second trench provided on the other side thereof being interposed therebetween. A reflectivity Rf at a front end face of a resonator, a reflectivity Rr at a rear end face of the resonator, a minimum value W1 of a width of the first trench in a region adjacent to the front end face, a minimum value W2 of a width of the second trench in the region adjacent to the front end face, a width W3 of the first trench at the rear end face, and a width W4 of the second trench at the rear end face satisfy Rf Wr. The ridge includes a region where a width decreases with distance from the front end side toward the rear end side.