When processing such as SiC epitaxial growth is performed at an ultrahigh temperature of 1500° C. to 1700° C., a film-forming gas can be decreased to heat-resistant temperature of a manifold and film quality uniformity can be improved. A substrate processing apparatus includes a reaction chamber for processing a plurality of substrates, a boat for holding the plurality of substrates, a gas supply nozzle for supplying a film-forming gas to the plurality of substrates, an exhaust port for exhausting the film-forming gas supplied into the reaction chamber, a heat exchange part which defines a second flow path narrower than a first flow path defined by an inner wall of the reaction chamber and the boat, and a gas discharge part installed under the lowermost substrate of the plurality of substrates.