SEMICONDUCTOR MANUFACTURING FACILITY

PROBLEM TO BE SOLVED: To solve the problems of a method for supplying high temperature dilution gas 5 to the inside of air discharge piping 3 to heat the air piping 3, that is, (1) the effective range is short, (2) a flowmeter 12 for measuring the flow rate of dilution gas 27 is necessary, (3) it is necessary to select the heater of a heating device 4 with a low power in order to constantly control the inside temperature of the air discharge piping 3, and (4) it is difficult to install the heating device 4 since it is high in temperature. SOLUTION: A metallic layer for satisfactorily transmitting heat is arranged to the periphery of air discharge piping 3. The temperature of high temperature dilution gas 5 and a power outputted by a power unit 81 are measured, and the flow rate of the dilution gas 27 is calculated. Only when the inside temperature of the heater is turned to be high, it is controlled so as to be made constant in the allowable highest temperature of the heater. The whole part of a heating device 4 is covered with a metallic case. COPYRIGHT: (C)2004,JPO