In a semiconductor light-emitting element, a first cladding layer in a first conductive type, a quantum well active layer, and a second cladding layer in a second conductive type are stacked on a semiconductor substrate in this order. A ridge-shaped stripe formed at the second cladding layer forms a waveguide. Rf Wr are satisfied, where the width of the ridge-shaped stripe at a front end face from which laser light is output is represented by Wf, the width of the ridge-shaped stripe at a rear end face is represented by Wr, the reflectance of the front end face is represented by Rf, and the reflectance of the rear end face is represented by Rr. Light in a fundamental transverse mode, a first high-order transverse mode, a second high-order transverse mode, and a third high-order transverse mode is guided in the waveguide.