Patent ID: 7368398

Claim:
A method for processing a substrate using a substrate processing apparatus including a reaction chamber for processing the substrate using a processing gas, a shower head which includes a gas diffusion plate having a plate shape and a plurality of through holes for passing the processing gas and which is for supplying the processing gas into the reaction chamber, and a substrate support which is provided in the reaction chamber and which is for placing the substrate so that the substrate faces the gas diffusion plate, the method comprising the process steps of: a) placing the substrate on the substrate support; and b) supplying the processing gas to the reaction chamber through the plurality of through holes formed in the gas diffusion plate to perform processing to the substrate, wherein the plurality of through holes are formed in both a center region of the gas diffusion plate and a peripheral region of the gas diffusion plate that surrounds the center region, and each of the plurality of through holes formed in the peripheral region of the gas diffusion plate has an inlet for the processing gas and an outlet for discharging and supplying the processing gas into the reaction chamber, an area of the inlet being larger than that of the outlet.