The invention relates to an arrangement for mounting electric heating elements in a furnace in which objects are intended to be heated, wherein the furnace wall includes a furnace insulation (4) comprised of high grade brick, and wherein the heating zones (6) of respective electric heating elements (2) are placed vertically and parallel with the inner surface of the furnace wall in operation. The invention is characterized in that the electric leads or conductors (7, 8) of each element (2) are mounted in a cassette (9) and extend in channels (10, 11) therein; in that the heating zone (6) of the heating element projects outwards and defines an angle with the longitudinal axis of the cassette (9); in that the furnace insulation (4) includes for each cassette a hole (12) which is larger at its outer end than at its inner end, therewith enabling the cassette (9) to be rotated in a vertical plane as the heating zone (6) of the element (2) is inserted through the hole (12) and into said operating position parallel with the furnace wall; and in that a wedge-like body (13) is provided, whose shape corresponds to the shape of the empty space created by the shape of the hole (12) and located between the hole (12) and the cassette (9) when the cassette is placed in operating position in the hole, said body (13) being placed in said empty space during operation.