A semiconductor lighting apparatus includes a plurality of semiconductor light emitting devices for outputting light having respective colors, a projector for synthesizing output light of the semiconductor light emitting devices and outputting synthesized light, and a calculating portion. The calculating portion controls a driving current to be supplied to the semiconductor light emitting devices in such a manner that a light quantity detected by optical sensors approximates to a predetermined target light quantity, and calculates a target temperature of the semiconductor light emitting devices to control temperature regulating portions in such a manner that a temperature detected by temperature sensors approximates to the target temperature.