PLASMA PROCESSOR

PURPOSE:To prevent a discharge between a work and the other electrode from occurring by a method wherein an auxiliary electrode is protruded around a work on the surface of a work supporter side of opposite electrode to cause a discharge between the auxiliary electrode and the other electrode. CONSTITUTION:An airtight chamber 10 is provided with a gas inlet to introduce etching gas as well as a gas outlet to exhaust the gas filled therein for setting up specified vacuum pressure. Within the chamber 10, a flat plate type upper electrode 13 and another flat type lower electrode 14 are opposingly placed in parallel with each other while the upper electrode 13 is connected to a high frequency power supply 15 and the lower electrode 14 is grounded. Besides, a work supporter is formed on the surface of lower plate 14 to support a photomask plate 16 as a work while an auxiliary electrode 19 is formed around the work supporter on the surface. Both upper and lower electrode 13, 14 may be impressed with high frequency power to be activated.