PURPOSE: To make possible the simultaneous measurement of a chromatogram by plural pieces of capillary columns provided in a heating vessel by injecting a sample to the columns from a syringe introducing prat provided separately from the heating vessel.

CONSTITUTION: The syringe introducing part 2 is provided separetely from the heating vessel 4 and one end of a capillary tube 3 is attached thereto. A branch point 5 is provided to the other end. Plural pieces of the capillary columns 6, 7 in the vessel 4 are connected to the point 5 in such a manner that the flow passages are paralleled. The output sides of the columns 6, 7 are so constituted as to ve connected to respective detector 8, 9. The carrier gas passes through a flow rate control part and through the inactivated tube 3 on which the liquid phase is not coated from the introducing part 2 attached with a carrier gas supply pipe 1 until the gas enters the inside of the vessel 4 from which the gas arrives at the branch point 5. The gas is bisected at said point and the bisected gases arrive at the detectors 8, 9 through the columns 6, 7 with lead pipes. The simultaneous measurement of the chromatogram by the respective columns is thus made possible.