Abstract: Disclosed are an exothermic conducting paste mainly comprising a synthetic resin and a heat stable metal oxide which is positive in temperature coefficient of electric resistance and has an electric specific resistance of not more than 5.times.10.sup.3 .mu..OMEGA.cm at ordinary temperature, and an electric resistance heating unit wherein a desirably shaped solid or solid surface is coated or impregnated with said paste. This heating unit has an uniform temperature distribution, is adjustable to any desired temperature below 350.degree. C., and further can be formed in various shapes.

Abstract: A solid-body heating unit used for the warmth preservation, heating and heat treatment, more particularly, for surface heater for plates or patterns, has a refractory base overlaid with an electroconductive layer, a protective layer overlaying the electroconductive layer and a power supply for passing electric current through the electroconductive layer, whereby the surface temperature of the plates or patterns is controllable.