The plasma generating apparatus and method of a plasma

A plasma apparatus having a slot antenna (30) for supplying an electromagnetic field into the plasma generating container. This slot antenna (30) is formed with a slit (36), such that the radiation surface (31) of the outer peripheral portion B, the amount of electromagnetic radiation per unit area, is smaller than the inter-radiating surface (31) of the central portion A and the outer peripheral portion B , electromagnetic radiation amount per unit area of ​​the central region C.