Electrochemical behavior of the platinum electrode, which is modified with a film of copper nitroprusside, and its dependence on the experimental conditions, such as the potential scan rate, the nature of the supporting electrolyte, etc., are studied by cyclic voltammetry and chronopotentiometry. Some electrode processes are observed at 0.2 to 0.3 and 0.65 to 0.7 V (SCE): these are transitions Cu(I) → Cu(II) and Fe(II) → Fe(III), respectively.