A technique includes loading a substrate into a process chamber, supporting the substrate by a mounting table having a heater therein in the process chamber, forming a film on the substrate by supplying a processing gas into the process chamber in a state where the mounting table having the substrate supported thereon is disposed in a first position and the heater is turned on, unloading the substrate on which the film is formed, and supplying a reactive gas into the process chamber in a state where the mounting table is disposed in a second position and the heater is turned on. The second position is closer to a ceiling portion in the process chamber than the first position.