A gas chromatograph for preventing leakage of carrier gas and secondary accident such as explosion is provided. A flow rate restricting valve having valve mechanism which mechanically restricts flow rate of carrier gas is disposed at the upstream side of sample inlet portion 1 of the carrier gas flow path 11 and apart from the flow rate control valve 6 which controls the flow rate of the carrier gas, which is inlet into sample inlet portion and analytical column according to signal from control unit 8. The excessive flow rate that is larger than the predetermined resulted from the leakage of carrier gas is mechanically restricted to a pre-set flow rate by using the flow rate restricting valve. The leakage of carrier gas e.g., helium and the secondary accident due to leakage of carrier gas e.g., hydrogen, are prevented.