Abstract: Provided is a substrate processing apparatus that can suppress formation of an Si thin film on the inner wall of a film-forming gas supply nozzle. The substrate processing apparatus comprises a process chamber configured to process a substrate, a heating member configured to heat the substrate, a coating gas supply member including a coating gas supply nozzle configured to supply coating gas into the process chamber, a film-forming gas supply member including a film-forming gas supply nozzle supplying film-forming gas into the process chamber, and a control unit configured to control the heating member, the coating gas supply member, and the film-forming gas supply member. The control unit executes a control such that the coating gas supply nozzle supplies the coating gas to coat a quartz member in the process chamber and the film-forming gas supply nozzle supplies the film-forming gas to form an epitaxial film on the substrate.