Abstract: The deposition of Ni–Mn–O thin films by molecular layering with equivalent feeding of organometallic reactants was studied. Bis(cyclopentadienyl)nickel (NiCp₂) and tris(2,2,6,6-tetramethyl-3,5-heptanedionato)manganese(III) [Mn(thd)₃] were used as organometallic reactants. Oxygen-containing plasma was used for forming oxygen-containing structures. The mean increment of the Ni–Mn–O coating thickness in one cycle exceeds the sum of the corresponding values known for NiO and Mn₂O₃. At equivalent feeding, the nickel content of the coating exceeds the manganese content. High Coulomb efficiency (100%) of samples with the Ni–Mn–O coating on a steel support as an electrode is due to high reversibility of the electrochemical processes occurring in the course of charging–discharging trials. With an 80-fold increase in the discharging current, the discharging capacity decreases by less than 30%.