Abstract: An electric furnace for induction heating of metallic products comprises a planar inductor providing a sliding magnetic field, the inductor being incorporated in a pair of transversely spaced walls defining between themselves a space into which the product to be heated is inserted, a layer of refractory material at that side of each wall which borders the space and an independent cooling screen sandwiched between each wall and the respective layer of refractory material, in which the screen is constituted by a plurality of parallel, adjacent metal tubes out of mutual contact with each other to define between themselves electrically insulating spaces, preferably filled with electrically insulating material, and in which the tubes extend normal to the flow of the primary current through the inductor. Preferably at least one of the walls together with the respective refractory layer and screen is movable toward and away from the other wall to accommodate metal products of different widths in the space.