The catalytic properties of the formed MnO2/ITO electrodes were tested in the process of electrocatalytic decomposition of hydrogen peroxide. Based on data from the literature , , the mechanism of the process of the electrochemical determination of H2O2 as follows. During the catalytic decomposition of hydrogen peroxide in the presence of MnO2, Mn +4 is reduced to Mn +3 , and possibly even to Mn +2 . However, when the anodic polarization is applied to the electrode, the reverse oxidation of Mn +3 to Mn +4 occurs. By the value of the recorded anode current we can quantitatively determine the decomposed H2O2. The electrochemical properties of the developed electrodes were first characterized by cyclic voltammetry in 0.1 M PB (pH 7) at a scan rate of 100 mV/s in the potential range from 0.3 V to 0.9 V vs Ag/AgCl/3M KCl. The dependence obtained on the electrode pH1_CV_60 is shown in Fig. .