It is intended to provide an electrode material, which is excellent in electrostatic capacitance and low resistance, by improving conductive fine particle deposition factor and also improving the close contact between the conductive fine particles and the conductive base. A binder for a porous electrode, which is obtained by dispersing conductive fine particles such as active carbon and graphite and non-conductive fine particles 3 such as aluminum and zinc oxide in a rubber type binder 1 having been made porous by cross-linking, is developed on a conductive base 5 to form a porous electrode.