There is provided a semiconductor light-emitting device including a temperature detecting section which is allowed to accurately estimate an element temperature. The semiconductor light-emitting device includes: one or a plurality of surface-emitting semiconductor light-emitting sections and one or a plurality of semiconductor temperature detecting sections on a semiconductor substrate, the surface-emitting semiconductor light-emitting sections emitting light in a direction normal to the semiconductor substrate, the semiconductor temperature detecting sections not emitting light to outside. The semiconductor light-emitting sections and the semiconductor temperature detecting sections have a PN junction or a PIN junction in a direction normal to the semiconductor substrate.