Plasma processing apparatus

A plasma processing apparatus that processes a processing target substrate using microwave plasma comprising:

• a processing container including a lower member which surrounds a processing space for processing the substrate and a removable upper member,
• wherein the removable upper member serves as a cover of the lower member;
• a placing table provided in the processing container, and configured to place the processing target substrate thereon;
• and
• an antenna provided above the placing table to face the placing table, and including a dielectric plate, the antenna being configured to radiate microwaves into the processing container through the dielectric plate to generate plasma of a processing gas supplied into the processing container,
• wherein the dielectric plate includes:
• a flat plate portion provided on a bottom surface of the antenna, and formed in a flat shape at least on a surface facing the placing table;
• and
• a rib formed along a peripheral edge of a surface of the flat plate portion that is opposite to the surface facing the placing table to protrude upwardly from the flat plate portion, the antenna being supported on the upper member of the processing container by the flat plate portion and the rib, and
• the antenna further includes a conductor plate that is provided on the surface of the flat plate portion that is opposite to the surface facing the placing table while being surrounded by the rib and configured to propagate the microwaves.