A gas chromatographic system for the analysis of gas species to be collected from the JET Torus and to be processed in the JET Active Gas Handling plant during the Active Operation Phase with deuterium and tritium plasmas was designed and built by CFFTP under contract with JET. A detailed description of the specifications of the system, of the system itself and of its performance will be given which was evaluated using several calibrated gas mixtures including test runs with tritiated species at JET.