A semiconductor laser with a window structure which can emit a light beam with a non-deviated outgoing angle. The semiconductor laser emits a light beam generated at an active layer via a window section. The window section includes a first semiconductor layer having a first carrier concentration and a second semiconductor layer on the first semiconductor layer as an extension of the active layer and which has a second carrier concentration lower than the first carrier concentration. The window section further includes a third semiconductor layer having a third carrier concentration. According to the third layer, a refractive index distribution of the light beam at the window section is symmetrical in the laminating direction, with the extension of the active layer as a center. Because the beam is uniformly propagated, the beam can be emitted without being deviated in the laminating direction.