An apparatus for inductively heating an electrically conductive workpiece in the form of a closed ring includes a U-shaped magnet core with two legs, an electrically conducting coil arranged on at least one leg of the core and connectable with an alternating current source, and a magnet yoke spaced from at least one freestanding end of a leg of the core, so that a closed magnetic circuit with at least one air gap is formed, with the height of the air gap chosen such that the workpiece can be moved in a non-contacting manner into the air gap.