MICROWAVE DISCHARGE DEVICE

PROBLEM TO BE SOLVED: To improve generation efficiency of microwave plasma and to provide a discharge device with low cost. SOLUTION: Microwaves flying from a microwave oscillator are intercepted in a space strangulated between a metal wave-guide rectangular tube 44 and a dielectric plate 41, in the forward direction at the central part of H-plane perpendicular-direction for the length of 2λ and more plane-wise and monotonously, and a great number of electric-field peaks appear on the dielectric plate 41 to facilitate plasma discharge, nonreflective terminal-shaped plasma is formed in a discharge tube composed of a discharge-portion metal-part box 42 with a nonreflective terminal shape, and all the standing waves are absorbed through the dielectric plate 41 to cause a nonreflective plasma discharge condition. Further, by cooling the discharge-portion metal-part case 42, temperature increase on the wall face of the discharge portion is suppressed and the density of active particles is increased.