Electrode structures of solid polymer electrolyte type for use in electrolysis are disclosed, (i) in which an adhering layer containing fine particles loaded with a .beta.-lead dioxide powder is formed on one surface of an ion-exchange membrane serving as a solid polymer electrolyte, and an electrodeposited layer of lead dioxide being formed on the surface of the adhering layer, and (ii) in which an electrodeposited layer of lead dioxide having dispersed therein fine particles loaded with a .beta.-lead dioxide powder is formed electrolytically between an ion-exchange membrane serving as a solid polymer electrolyte and a current collector positioned close to the ion-exchange membrane, to thereby form a unitary assembly. The present electrode structures are useful for production of ozone by electrolysis of water and for production of peroxides by electrolysis of aqueous solutions.