A modified apparatus for the quantitative determination of carbon and hydrogen contents of either volatile or non-volatile substances is introduced.The part of the modified apparatus for the entrance of the sample (Fig.1) is lengthened in such a way that the strongly volatile sample can be cooled before analysis without any loss and that the non-volatile liquid or solid sample can be heated electrically to render complete volatilization.Furthermore,the modified apparatus can also be used for the analysis of substances containing tin,arsenic,sulfur,fluorine and other halogens.