Gas distribution supply device and gas distribution supply method for supplying air to chamber by gas supply equipment with flow control device

The present invention is for supplying a specified quantity Q of processing gas while dividing at a desired flow rate ratio Q 1 /Q 2 accurately and quickly from a gas supply facility equipped with a flow controller into a chamber. With the present invention, a total quantity Q=Q 1 +Q 2 of gas while dividing is supplied into a chamber C at a desired flow rate Q 1 and Q 2 through shower plates 3 and 4 fixed to the ends of branch supply lines GL 1 and GL 2 by providing open/close valves OV 1 and OV 2 with a plurality of branch supply lines GL 1 and GL 2 respectively to supply a specified quantity Q of gas G from a gas supply facility 1 equipped with a flow controller QCS into a chamber, and by utilizing a bypass line BL 1 on the downstream side of the afore-mentioned open/close valve OV 1 and branched from GL 1 , a bypass line BL 2 on the downstream side of the open/close valve OV 2 and branched from GL 2 , a pressure type division quantity controller FV connected to the bypass line BL 1 and the bypass line BL 2 , a pressure sensor PS 1 to measure pressure inside the branch supply line GL 1 , and a pressure sensor PS 2 to measure pressure inside the branch supply line GL 2 .