TWI793744B

There is provided a technique, which includes: a process chamber where a substrate is processed; a microwave oscillator configured to supply microwaves to the process chamber; and a controller configured to be capable of controlling the microwave oscillator to perform: a heating process where the substrate is heated with a first microwave, among the supplied microwaves, supplied at a first microwave power so that a process of supplying the first microwave during a supply time and a process of stopping the supply of the first microwave during a stop time shorter than the supply time are performed a predetermined number of times or for a first predetermined time; and a modifying process in which the substrate is supplied with a second microwave, among the supplied microwaves, at a second microwave power higher than the first microwave power for a second predetermined time while maintaining the second microwave power.