The present invention provides a semiconductor manufacturing apparatus which stabilizes the quality of thickness of a film between solids, which is produced on a wafer in the semiconductor manufacturing apparatus by a CVD method using light, and improves in-plane thickness uniformity to thereby bring about excellent production efficiency. The semiconductor manufacturing apparatus is provided with a gas supply pipe for supplying a material gas to a chamber used to store the wafer placed in the semiconductor manufacturing apparatus, and a transparent plate which is provided in the chamber and allows the light to pass therethrough. The transparent plate is heated by a heater to thereby prevent the production of the film on the transparent plate and control the concentration of a material gas in the vicinity of an object to be processed.