A method and device for detecting explosive compounds in an air sample in which the air sample is filtered with activated carbon treated with a weakly basic solution, after which the air sample is divided into two parts, with one part being heated at lower temperatures to decompose non-explosive nitrogenous compounds and the second part being heated at higher temperatures to decompose explosive nitrogenous compounds. Nitrogen dioxide is measured in both portions of the air sample with a spectrographic detector, and the presence or absence of explosive nitrogenous compounds in the air sample is determined.