Plasma-processing apparatus

A plasma-processing apparatus comprising a vacuum vessel having a reaction space formed between a high frequency power application electrode and an earth electrode which are arranged in said vacuum vessel such that they are opposed to each other, said high frequency power application electrode having a face exposed to said reaction space, wherein a VHF power is supplied to said high frequency power application electrode to generate a plasma in said reaction space, characterized in that between other face of said high frequency power application electrode excluding said face thereof exposed to said reaction space and a conductor with earth potential comprising at least part of the circumferential wall of said vacuum vessel, an impedance matching equipment comprising a capacitive element and an inductive element which are mutually connected in series connection is arranged such that said capacitive element and said inductive element of said impedance matching equipment are symmetrical to the center of said high frequency power application electrode.