Plasma processing system

Patent Granted To suppress propagation of a conductor surface wave. A plasma processing apparatus (10) is provided with a processing container (100) formed of metal; a microwave source (900) for outputting a microwave; a dielectric plate (305) which faces the inner wall of the processing container (100) and transmits the microwave outputted from the microwave source (900) into the processing conainer; and a groove (300a) which functions as a propagation disturbing section arranged on the inner surface of the processing container. When a low frequency microwave is supplied, propagation of a conductor surface wave is suppressed by the groove (300a).