A gas-line system used for a semiconductor-manufacturing apparatus with at least two reactors, includes at least one gas source; a flow-divider means including an input port on the primary side, which receives a source gas from the gas source, and an output port on the secondary side, which outputs an inputted source gas by equally distributing it. The input port on the primary side is connected with the gas source and the output port on the secondary side is connected with the reactors; and one exhaust pump for exhausting gases within the reactors, which is connected with the reactors. It is desirable that the gas-line system is provided between the reactors and the exhaust pump, and an APC is included for controlling pressure for each reactor.