The present invention relates to a microwave plasma processing method and apparatus. More particularly, it relates to a microwave plasma processing method and apparatus of the type wherein a waveguide section includes electric discharge means (30a) isolated from a waveguide (110a) for the propagation of microwaves and having a plasma generation region therein, which method and apparatus are well suited for subjecting samples (90), such as semiconductor device substrates, to an etching process, a film forming process, etc.
According to the present invention, the microwaves are introduced into the electric discharge means (30a) in correspondence with only the traveling direction thereof, whereby uniformity in a plasma density distribution corresponding to the surface to-be-processed of the sample (90) can be sharply enhanced, so that the sample processed by utilizing such plasma can attain an enhanced processing homogeneity within the surface processed.