Closed container to be used in a clean room

A portable container adapted to store wafers in a clean room of a semiconductor manufacturing system comprising:

• a container body having an opening for accessing a storage area defined within said container;
• a lid member attached to said container body and adapted to extend across said opening so as to close said container;
• a seal member positioned between said lid member and said container body such that, when said lid member is positioned so as to extend across said opening, said storage area is sealed;
• a passage having a first end opening into said storage area and a second end opening outside of said container;
• a tank connected to the second end of said passage and supported by said container body so as to be portable therewith, said tank containing a pressurized supply of inert gas;
• and
• means for regulating the pressure of inert gas in said storage area such that, when an item is placed in said storage area, said container is sealed and said storage area is filled with an initial supply of inert gas, a supplemental supply of inert gas will automatically be discharged into said storage area from said tank upon a predetermined decrease in inert gas pressure within said storage area due to leakage.