A plasma processing apparatus comprising: a vacuum container; an evacuation means for keeping the interior of the vacuum container at a pressure not higher than atmospheric pressure; a substrate support device for supporting a substrate to be subjected to plasma processing; an electrode for generating plasma in cooperation with the substrate support; a voltage supply for applying a voltage to the electrode; a gas introducing system for introducing a gaseous material into a space where the plasma is produced; a surrounding member for enclosing the space above the substrate support, and a drive for relatively moving the surrounding member to space an end of the surrounding member proximate from the substrate from at least one of the substrate support and the substrate supported thereon by a distance which is short enough to suppress plasma leakage during the plasma processing and to position the end of the surrounding member away from said at least one of the substrate support and the substrate thereon for charging and discharging of the substrate.