A gas divided flow supplying apparatus, including a control valve 3, a pressure type flow control unit 1a connected to a process gas inlet 11, a gas supply main pipe 8 connected to the downstream side of control valve 3, a plurality of branched pipe passages 9a, 9n connected in parallel to the downstream side of main pipe 8, opening and closing valves 10a, 10n interposed in the respective branched pipe passages 9a, 9n, orifices 6a, 6n provided on the downstream sides of valves 10a, 10n, a temperature sensor 4 provided near the process gas passage between the control valve 3 and the orifices 6a, 6n, a pressure sensor 5 provided in the process gas passage between the control valve 3 and the orifices 6a, 6n, divided gas flow outlets 11a, 11n provided on the outlet sides of the orifices 6a, 6n, and an arithmetic and control unit 7.