PURPOSE: To prevent a change in the adhesion of a resist due to changes in the concentration and the pressure of the atmosphere of chemicals in a closed type chamber of equipment for treatment before application of the resist.

CONSTITUTION: A wafer 1 before application of a resist is held in a closed type chamber 3 and the atmosphere of chemicals is sent by piping 5 for the atmosphere of chemicals. The concentration of the atmosphere of chemicals in the chamber is measured by a concentration sensor 12 provided at the upper part of the chamber, and a mass flow controller 14 controlling the flow rate of joining nitrogen is controlled by a concentration control circuit 11. Besides, the pressure in the closed type chamber is measured by a pressure sensor 17, while a variable flow control valve 15 provided in the middle of an exhaust piping 4 is controlled by a pressure control circuit 16.