PURPOSE: To achieve a higher reliability of analysis, by controlled management of a plurality of gas chromatograph units by a common means to perform an injection of a sample.

CONSTITUTION: A sample container B is moved to a sampling position with a tray 25 with an applied analysis condition code read by a code reader 31. A controller 30 selects a gas chromatograph unit 12 optimal for the conditions read with the device 31 and a sample transfer mechanism 20 is operated to sample a fixed amount of sample with a syringe 22 from the container B. Then, a mechanism 22 positions an injection needle of the syringe 22 with a sample injection port 12a by the device 30 to inject a sample into the unit 12. Thereafter, the same operation is performed sequentially. When the optimum gas chromatograph unit is in operation, the subsequent analysis is performed and after a fixed time, the analysis of the second sample once retained is restarted. The managed control of a plurality of chromatograph units different in the analysis conditions is performed with a common controller thereby achieving a higher reliability of analysis.