The invention is an electrochemical capacitor with its electrodes made on a conducting substrate with a layer of a redox polymer of the poly[Me(R-Salen)] type deposited onto the substrate. Me is a transition metal (for example, Ni, Pd, Co, Cu, Fe), R is an electron-donating substituent (for example, CH3O—, C2H5O—, HO—, —CH3), Salen is a residue of bis(salicylaldehyde)-ethylendiamine in Schiff's base. The electrolyte comprises of an organic solvent, compounds capable of dissolving in such solvents with the resulting concentration of no less than 0.01 mol/l and dissociating with the formation of ions, which are electrochemically inactive within the range of potentials from −3.0 V to +1.5 V (for example, salts of tetramethyl ammonium, tetrapropyl ammonium, tetrabutyl ammonium), and a dissolved metal complex [Me(R-Salen)]. The method of using the capacitor contemplates periodically alternating the connection polarity of the electrodes, causing the electrochemical characteristics of the electrodes to regenerate.