Patent ID: 8568556

Claim:
A plasma processing apparatus for plasma-processing an object by exciting a gas using an electromagnetic wave, the plasma processing apparatus comprising: a processing container sealed with a lid and comprising a metal; an electromagnetic wave source for outputting an electromagnetic wave to the processing container through a wave guide, wherein the electromagnetic wave output by the electromagnetic wave source has a frequency of equal to or less than 1.9 GHz; a holding stage which holds the object; a dielectric plate disposed on a bottom surface of the lid and facing the holding stage of the processing container and transmitting the electromagnetic wave, which is output from the electromagnetic wave source, into the processing container; a surface wave propagation region adjacent to and surrounding the dielectric plate and consisting of a metal surface of the bottom surface of the lid of the processing container which faces the holding stage and is exposed to plasma, the electromagnetic wave propagating along the surface wave propagation region; and a groove portion or a convex portion formed on the metal surface of the bottom surface of the lid of the processing container which faces the holding stage and is exposed to plasma, and surrounding the dielectric plate and the surface wave propagation region, wherein the groove portion or the convex portion suppresses propagation of the electromagnetic wave; and the convex portion consists of a metal.