Described herein is a technique capable of improving the productivity of manufacturing of a semiconductor device in a method of processing a film by repeating different processes. A method of manufacturing a semiconductor device may include: (a) loading a substrate into a process vessel; (b) forming a first layer by supplying a first gas into the process vessel by a gas supply unit while maintaining the substrate at a first temperature by a temperature control unit; and (c) forming a second layer different from the first layer by supplying a second gas different from the first gas into the process vessel by the gas supply unit while maintaining the substrate at a second temperature different from the second temperature by the temperature control unit.