Film Forming and Cleaning Method

A film forming and cleaning method according to the present invention comprises a temperature adjusting step performed between a film forming step and a cleaning step. In the film forming step, a process gas is supplied into a process vessel (1) to form a film on a substrate (W) in the process vessel (1), while a first part (4) inside the process vessel (1) is heated to a first temperature (for instance, 200 degrees Celsius) and a second part (side wall) inside the process vessel (1) is also heated to a second temperature (for instance, 90 degrees Celsius) lower than the first temperature. In the temperature adjusting step, the temperature of the first part (4) is lowered to a level closer to the second temperature. In the cleaning step, a cleaning gas is supplied into the process vessel (1) to remove deposits deposited on the surfaces of the first part and the second part.