Abstract: Disclosed is a conductive rubber roller, comprising a core metal shaft, an ionic conductive layer formed to surround the outer circumferential surface of the core metal shaft and consisting of a high molecular weight elastomer containing an ionic conducting agent or a foamed body of such a high molecular weight elastomer, an electron conductive layer formed to surround the outer circumferential surface of the ionic conductive layer and consisting of a high molecular weight cellular elastomer containing an electron conducting agent or a high molecular weight cellular elastomer containing an electron conducting agent, a toner contamination preventing layer formed to surround the outer circumferential surface of the electron conductive layer, and an insulating annular sealing member mounted to each of both edges of the ionic conductive layer and the electron conductive layer both extending in the longitudinal direction of the metal core wherein a relationship R1>R2>R3, where R1, R2 and R3 denote, respectiv