Abstract: The invention relates to a method of trace analysis of organic compounds which calls for the steps of setting a test piece in a flow cell, and thereafter removing organic compounds from the test piece by heating it at high temperature in an oven. The compounds are concentrated in a trap tube and then removed from the trap tube and carried into a concentrating/inlet unit, such as a thermal desorption cold trap injector. In this unit, cryofocusing of the compounds is performed, and then the organic compounds are introduced into a gas chromatograph to be analyzed therein, wherein a part of the purified inert gas is caused, except during the process of trapping the organic compounds, to flow into the flow cell from the direction opposite the direction from which the gas flows along the trapping line.