The structural effects induced by ion exchange of NH4+ by Co2+ cations in the series of ferrierites were investigated by electron spectroscopy for chemical analysis (ESCA). The utility of the Auger parameter alpha' of framework Al for the estimation of the extent of ion exchange of NH4+ by Co2+ cations is demonstrated. The effect of framework --> Co2+ charge transfer on intensities of Al KLL Auger lines is discussed. The influence of coordination mode of Co2+ on the shape of Auger Co L-3 M4,5M4,5 spectra is shown.