A complete study of ionization in flames involves solution of the problems: (1) identification of the ions (as yet nothing definite is known about their nature); (2) evaluation of the ion concentration (even now there is still some disagreement concerning the exact amount of ions in a flame); and (3) determination of the mechanism by which ions are formed in the flame. There seems to be no question about ‘chemi-ionization’; not much, however, is known about the mechanism which can lead to ion formation. It is precisely in view of this that a new technique has been developed in the laboratory. It is based essentially on the extraction of the ions from the flame and their separation from the burnt gases. We have succeeded in producing the extracted ions in a vacuum of 10−5 mm of mercury and we hope to be able to identify them by a mass spectrometric method in a further development of our equipment. This paper describes the extraction apparatus and gives some indications concerning the concentration of the ions in a flame as measured by a completely new technique.