Abstract: The present invention relates to a method of producing an electrolytic electrode containing the following steps: forming a lead plating layer on the surface of a metallic core material by using a lead electrolytic plating bath, where the metallic core material is the cathode; forming an .alpha.-lead dioxide layer on the lead plating layer by electrolysis using an alkaline bath containing a lead ion and using the core material as the anode; and forming a .beta.-lead dioxide layer on the .alpha.-lead dioxide layer by electrolysis using an aqueous lead nitrate solution and using the core material as the anode. The electrolytic electrode produced by the foregoing method is capable of electrolysis in an aqueous solution, in particular, in an aqueous corrosive solution containing fluorine ions.

Abstract: There are provided an electrode substrate for electrolysis comprising an electrically conductive metallic base material and a coating layer having a thickness of from 10 to 200 .mu.m composed of a platinum group metal and partial oxides of a non-stoichiometric composition containing at least one kind of metal selected from the group consisting of titanium, tantalum and niobium, and oxygen formed on the surface of the base material and a method of producing the electrode substrate. The electrode substrate has a sufficient durability and a chemical stability under a high electric current density, and can be stably used for a long period of time for use under a cathodic polarization in an electrolysis, etc., with a positive-negative inversion, and the use in an electrolyte containing corrosive materials.