Abstract: In a method of production of finely divided metal oxides, metal hydroxides and metals, current is passed between an anode of a selected metal and an air electrode acting as the cathode in a cell containing a weakly alkaline electrolyte. The anion of the electrolyte is such that it does not form an insoluble salt with the metal of the anode. Metal ions issuing from the metal anode make contact with hydroxyl ions in the solution and form finely divided oxides or hydroxides. The oxides or hydroxides are removed and chemically reduced to finely divided metal particles. The voltage necessary for carrying out the oxidation of the metal to metal ions is reduced through the use of an air electrode as cathode, thereby reducing the cost of the process.