| 摘要 |
A thermal processing unit according to the invention includes: a processing furnace; gas-supplying means that supplies a process gas into the processing furnace; heating means that heats an inside of the processing furnace to a predetermined process-temperature; a normal-pressure gas-discharging system for discharging gas from the processing furnace at a predetermined discharging-pressure that is near to an atmospheric pressure; a valve provided in the normal-pressure gas-discharging system, the valve being adjustably caused to open and close, a pressure of the gas through the valve being also adjustable; a pressure sensor that detects a discharging-pressure in the normal-pressure gas-discharging system; and a controller that controls the valve based on the pressure detected by the pressure sensor. In the pressure sensor, a gas-contact surface that may come in contact with the discharged gas is made of a corrosion-resistant material that is not metal. According to the invention, a stable control can be achieved without necessity of introducing atmospheric air or introducing any inert gas. In addition, a structure of the gas-discharging system is simplified, reduction of costs is achieved, there is no concern about corrosion of the pressure sensor even in severe corrosion environment, and a stable process can be achieved at any time.
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