An ionic source of a new type for earth atmosphere pollution monitoring systems was studied by ion mobility spectrometry. The results of computer simulation of ion formation in the plasma of barrier discharge in an N₂-O₂ mixture at atmospheric pressure were discussed. It was shown that the afterglow phase of the barrier discharge at atmospheric pressure can be regarded as an effective plasmochemical reactor of positive and negative ions with a wide mass composition. Ion mobility spectra were given for a number of the components of atmospheric air pollutants obtained using the new ion source. The ion source can be used in earth atmosphere pollutant monitoring and this application was found to be promising.