PURPOSE: To reduce the required quantity of an inert gas by installing both feed and discharge valves, feeding and discharging the inert gas, in a housing body, in case of a housing for curing a work made of copper or the like in an inert gas atmosphere.

CONSTITUTION: A gas feed valve 8 and a gas discharge valve 9 are installed in a cover 7 of a work housing body 5. This gas feed valve 8 is provided with a built-in on-off valve being normally closed but opened by feed gas pressure, while the gas discharge valve 9 is provided with a built-in on-off valve being normally closed but opened by internal gas pressure. A work is housed in the housing body 5, the cover 7 is closed and, after being positioned on a curing heating body, an inert gas feed chuck 12 is connected to the feed valve 8 and an inert gas suction chuck 13 to the discharge valve 9, respectively, feeding the inert gas, and this inert gas to be discharged out of the discharge valve 9 is attracted by suction. With this constitution, the work is placeable in a sufficient inert gas atmosphere with a small quantity of gas.