Patent ID: 7302910

Claim:
A plasma apparatus, comprising: a container ( 11 ) having an opening; a dielectric member ( 13 ) supported by an end surface of an outer periphery of the opening of said container and closing said opening; an antenna for supplying an electromagnetic field from said opening into said container through the dielectric member; and a shield member ( 12 ) extending at least between the end surface of said container and said antenna, covering an outer periphery of said dielectric member and shielding said electromagnetic field; wherein a distance from an inner surface of said container at the end surface of said container to an inner surface of said shield member corresponds to approximately N/2 (N is an integer not smaller than 0) times the wavelength of said electromagnetic field in an area surrounded by the end surface of said container, said antenna and said shield member, such that a distance L1 from the inner surface of said container to the inner surface of said shield member satisfies the relation: ( N /2)·λ g −ΔL<L 1 <( N /2)·λ g +ΔL , where L 1 >0, Δ L =(θ/360)·λ g , θ=sin −1 (1/Γ), and Γ=1+{0.328/(δ· D 1/2 }, wherein D is a distance between the end surface of said container ( 11 ) and said antenna, δ is the relative air density in said area, and λ g is a wavelength of said electromagnetic field in said area.