PURPOSE: To develop a plasma processor by stably supplying high-density plasma even to a region which is low in pressure and weak in magnetic field over large area and large volume without arrangement of a electrode.

CONSTITUTION: A cathode 1 for DC discharge having a gas pressure gradient, a middle electrode 2, and an anode, and an anode ring 4 are arranged at the end of a main (vacuum) container 7, and a discharge plasma flow diffuses into the main container from the center hole of the anode ring. Parallel strong magnetic fields is applied to the anode region, so it becomes PIG discharge. The direction and shape of the plasma flow 8 diffused into the main container are adjusted by a permanent magnet.