Abstract: A light emitting diode for a photosensor is so constructed that ambient temperature drifts are prevented from adversely affecting a measurment. The light emitting diode for a photosensor has a substrate (12) carrying a light emitting element (LED.sub.2) and a light receiving element (PD) for sensing light emitted by the light emitting element (LED.sub.2) thereby to detect a change in the amount of light from the light coming emitting element (LED.sub.2) in accordance with a change in the ambient temperature. For this purpose a first transparent layer (21) is provided on the substrate (12) to cover the light emitting element and the light receiving element (PD). A second transparent layer (22) is provided on the first transparent layer (21). A very thin air layer is interposed between the first and second transparent layer.