To minimize thermal deformation of a coil-like resistance heating element of an electric furnace.

In this electric furnace, coil-like resistance heating elements 3 are provided in and along grooves 23 formed on an inner face of a heat- resistant furnace wall 1, and heating wires 31 forming the heating elements 3 are partially embedded in opposed side walls 24, 24 of the grooves 23. The heating wires 31 of the heating elements 3 are bridged across the opposed side walls 24, 24 of the grooves 23 in an approximately linear condition. Because the heating wires 31 forming the heating elements 3 are bridged across the opposed side walls 24, 24 of the grooves 23 in an approximately linear condition, even when the heating wires 31 are softened by heat generation or elongated by thermal expansion, it is possible to present the wires from coming into contact with a conductive material in the furnace and short circuiting.