Plasma apparatus and production method thereof

A plasma apparatus, comprising: a container (11) with an opening portion, whereby the outer periphery of the end face of the opening portion of the container supported and clog the dielectric member (13) of the opening through which the dielectric member (13) the outer periphery of the container (11) is supplied inside the electromagnetic field supply means, and a dielectric cover member (13), the shield shielding material (12) electromagnetic field. Wherein a distance from the inner surface of the inner surface of the container (11) of the container (11) to an end face of the shielding material (12) is L