An electroconductive roller including an electroconductive cellular material layer, comprised of a polyurethane composition, which has an average foamed cell diameter not more than 100 .mu.m and a variation .DELTA.D of the foamed cell diameter not more than 50 .mu.m. The electroconductive roller has a hardness variation .DELTA.Hs not more than 8 degrees and a circumferential non-uniformity index R.sub.MAX/R.sub.MIN in an electric resistance thereof not more than 1.3. The electroconductive cellular material layer is made of a thermosetting one-part polyurethane composition. And the polyurethane composition is cured instantly at a temperature not less than a thermosetting critical temperature for curing thereof, after it is foamed by a mechanical foaming method.