A technique is described which permits extraction of ions from a flame burning at atmospheric pressure, and identification of these ions by a time‐of‐flight mass spectrometer. The sampling system (consisting of a differentially pumped inlet system for rapidly reducing the pressure, a series of ion lenses for collimating the incoming beam, and a grid system for decelerating and bunching the ions as they enter the mass spectrometer) is described in detail, and performace data for the system are presented.