PURPOSE: To provide an efficient plasma producing equipment of a simple structure that calls for less fabricating cost and maintenance cost and produces plasma with uniform density and less diffusion.

CONSTITUTION: A plasma diffusion shielding wall 31 is placed around a space where plasma is to be produced in a plasma producing equipment including a coil 26 for producing plasma. Thus plasma is contained and produced within the space enclosed with the wall. This prevents the diffusion of plasma and improves the efficiency of producing plasma.