The nature of intermediate products of interaction between the metal and solution components during the anodic dissolution and their role in this process was examined. The problems concerning the accelerating and inhibiting action of the solution components were considered. The results of studies of iron in aqueous media by means of electrochemical methods (including measurements on the electrode with continuously renewed surface) and electroreflectance spectroscopy are listed and analysed. It is shown that the results obtained are in accordance with the Kolotyrkin theory of metal dissolution which takes into account the energetical heterogeneity of the metal surface and the formation of surface charge-transfer complexes.