The preparation of silver (II, III) oxide having the composition Ag3O4 is effected by anodic oxidation of silver fluoride solutions having silver concentrations of 0.01-0.35 mol/l and fluoride concentrations of from 0.01 to 4 mol/l at temperatures of from -4 to +30 DEG C, pH values between 4 and 7 and current densities of from 40 to 2000 A/m<2>.
