Abstract: In the exhaust gas treatment method of the present invention, exhaust gas in an excited state in semiconductor device production equipment is introduced into a plasma treatment unit of a treatment unit under reduced pressure, introduced into a reactor of a reaction removal unit while maintained in an excited state by plasma generated in the plasma treatment unit, and is reacted with a reaction remover composed of particulate calcium oxide filled into the reactor to remove harmful gas components in the exhaust gas. Exhaust gas may also be reacted with the reaction remover after having degraded the harmful gas components by oxidative degradation in the presence of plasma by supplying oxygen to the plasma treatment unit.

Abstract: The exhaust gas treatment agent of the present invention is an exhaust gas treatment agent provided with a particulate and porous structure, and composed of calcium hydroxide occupying at least a portion of the surface thereof, and calcium oxide occupying the remainder. The specific surface area if preferably 1 m2/g or more, and the void fraction is preferably 10 to 50% by volume. This calcium oxide is obtained by baking particulate calcium carbonate, and exhaust gas discharged from a semiconductor production device is removed of harmful gas components by allowing the exhaust gas to contact and react with this exhaust gas treatment agent while in the gaseous state.

Abstract: A valve for a gas cylinder consisting essentially of a valve body provided with a valve chamber containing a valving element which opens and closes an annular valve seat, and a gas cylinder plugging end portion and a pipe-connecting port both formed on the valve body. The gas cylinder plugging end portion contains an upstream side gas channel communicating at one extremity to an end thereof and at the other extremity to an internal circumference of the valve seat. The port contains two downstream side gas channels each opening to an end thereof and at the other extremity to an external circumference of the valve seat. A metal connector can be fitted in the port. The metal connector contains two channels connected to the two downstream side gas channels respectively. Valve chamber openings of the downstream side gas channels are located to oppose each other across the valve seat.