Plasma processing apparatus and manufacturing method of semiconductor device

A manufacturing method of a semiconductor device, the manufacturing method comprising:

• loading a substrate into a processing container in which the substrate is processed;
• placing the substrate on a lower electrode facing an upper electrode in the processing container;
• supplying a first process gas from a plurality of gas supply holes arranged on a first surface of the upper electrode, the first surface facing the lower electrode;
• generating plasma of the first process gas in the processing container during a first period by supplying electric power to at least one of the upper electrode and the lower electrode;
• stopping generation of the plasma and supply of the first process gas after the first period has elapsed;
• supplying a second process gas from the plurality of gas supply holes arranged on the first surface;
• generating plasma of the second process gas in the processing container during a second period by supplying electric power to at least one of the upper electrode and the lower electrode;
• and
• after the generation of the plasma and the supply of the first process gas are stopped, and before the supply of the second process gas, exhausting the first process gas in a diffusion portion via a plurality of gas exhaust holes arranged on a second surface on an opposite side to the first surface and separated from the first surface by the diffusion portion, the diffusion portion in which the first process gas is diffused.