Electrochemical oxidation and reduction reactions of Cu were studied in chloride-containing media by observing changes to the surface morphology of graphite and Cu working electrodes using in-situ electrochemistry atomic force microscopy (ECAFM). AFM images combined with cyclic voltammograms identified three overpotential (η) regions corresponding to the anodic dissolution of Cu in low-concentration (0.002 M HCI) chloride solutions. At low η, «the Tafel region», AFM images showed the dissolution of Cu, which was accompanied by an exponential increase in current density. At higher η, the current-limiting region, AFM images showed the growth of CuCl crystals, which was accompanied by an abrupt decrease in current density