Abstract: The electrochromic indicator according to the invention is a multilayer structure and comprises in a sandwich layered arrangement an optically transparent first substrate, an optically transparent first electrode, a layer of a solid inorganic electrochromic material, and a layer of an electrolyte. Interposed between the electrolyte layer and a second electrode is a layer which is a film of an oxidation-reduction polymer, or a filled polymer film, or a paste containing an oxidized form (Ox) and a reduced form (Red) of compounds which produce on the second electrode a reversible oxidation-reduction reaction of the following type:Red.revreaction.Ox+me,wheree is an electron, andm is the quantity of electrons involved in the reaction, with an exchange of electrons by means of the second electrode, and also containing compounds which are sources of cations similar to cations of the electrolyte layer. A second substrate adjoins the second electrode.