CLEAN ROOM

PURPOSE:To maintain the stability of air pressure between processing spaces to prevent the air flow turbulence so that dusts may not attach to wafers by disposing shutter plates whose size is made adjustable to at least either one of air outlets in the side walls of the respective processing spaces with are erected in the opposed positions in the room where clean air flows. CONSTITUTION:Shutter plates 29 are disposed to an air outlet 33c in a side wall component 23b on the side where a processing device 26 is not placed, and the diameter of the air outlet 28b is suitably adjusted. In this manner, the air pressure in both the processing spaces 26a, 26b can be stabilized. Therefore, dusts are prevented from staying due to the air flow turbulence etc. When the air purification is achieved in this manner, as the air flow turburance in the working chamber 22 can be prevented on account of the shutter plates 29 at the time when the conditioned air 45 of class 100 or so is delivered from the air conditioner 36, the clean air of a class higher than the afore-said air can be obtained in the working space 27 and processing spaces 26a, 26b. When the air recirculation is repeated several times, a clean level equivalent to class 10 can be maintained in the processing spaces 26a, 26b.