Reduced pressure processing system and reduced pressure processing method

A reduced pressure processing system comprising:

• a load lock chamber having outer and inner walls and at least one opening communicating with at least one of an outer air atmosphere and a process atmosphere in which a substrate is processed;
• gate means for closing said opening so as to separate an interior of said chamber from at least one of the outer air atmosphere and the process atmosphere, and for opening said opening so as to make the interior of said chamber communicate with at least one of the outer air atmosphere and the process atmosphere;
• convey means for loading/unloading the substrate through said opening into/out of a first space which is surrounded by said inner wall and said gate means;
• evacuation means for evacuating said chamber, said evacuation means including a first evacuator for evacuating said first space and a second evacuator for evacuating a second space which is surrounded by said outer and inner walls;
• gas supply means for supplying a gas into said first and second spaces;
• first heating means for heating said inner wall;
• and
• differential pressure detecting means for detecting a difference in pressure within said first and second spaces and providing a signal of said pressure difference to a control means for controlling at least one of said evacuation means and said gas supply means;
• wherein the inner wall is thinner than the outer wall.