A semiconductor laser element 10 according to the present invention comprises a waveguide 12 of a high mesa type. And then such the waveguide 12 comprises an oblique end face 17 as an emitting facet that is different from a cleaved end face 16. And hence it becomes possible to reduce a reflection factor at the end face by making of such the oblique end face 17, and it becomes possible to design a direction of an emitting beam 21, that is to be emitting from the oblique end face 17, to be independent of that for the cleaved end face 16 as well. Moreover, the emitting beam 21 is designed to be emitting as vertical to the cleaved end face 16. And then therefore in a case where an emitting beam from a semiconductor optical device is designed to be coupled with such as an optical fiber or another waveguide or the like, it is not necessary to device such as that the semiconductor laser element 10 is required to be arranged at a sub mount by being inclined to be oblique or the like.