An electromagnetic shield for shielding a magnetic field produced around one or more coils (12a, 12b) having ac current flowing in the one or more coils (12a, 12b), through which a workpiece moves for induction heating of the workpiece by the magnetic field, the electromagnetic shield comprising a first and a second transverse screen element through which the workpiece moves, the first and second transverse screen elements (10a, 10b) being disposed at opposing ends of the one or more coils (12a, 12b) and laterally to an edge of the workpiece, characterized by: a discontinuity (h 2) in each of the first and second transverse screen elements (10a, 10b); a first longitudinal screen section connecting a first end of the first transverse screen element at the discontinuity (h 2) in the first transverse screen element to a first end of the second transverse screen element at the discontinuity (h 2) in the second transverse screen element, the first longitudinal screen section being disposed laterally to an edge of the workpiece; and a second longitudinal screen section (10c") connecting a second end of the first transverse screen element at the discontinuity (h 2) in the first transverse screen element to a second end of the second transverse screen element at the discontinuity (h 2) in the second transverse screen element, the second longitudinal screen section (10c") being disposed laterally to the edge of the workpiece and adjacent to the first longitudinal screen section, whereby current induced in the electromagnetic shield by the magnetic field flows in the closed circuit path established by the first transverse screen element, the first longitudinal screen section, the second transverse screen element and the second longitudinal screen section (10c"), and opposing electromagnetic fields established by opposing currents in the first and second longitudinal screen sections (10c', 10c") substantially cancel each other. a discontinuity (h 2) in each of the first and second transverse screen elements (10a, 10b); a first longitudinal screen section connecting a first end of the first transverse screen element at the discontinuity (h 2) in the first transverse screen element to a first end of the second transverse screen element at the discontinuity (h 2) in the second transverse screen element, the first longitudinal screen section being disposed laterally to an edge of the workpiece; and a second longitudinal screen section (10c") connecting a second end of the first transverse screen element at the discontinuity (h 2) in the first transverse screen element to a second end of the second transverse screen element at the discontinuity (h 2) in the second transverse screen element, the second longitudinal screen section (10c") being disposed laterally to the edge of the workpiece and adjacent to the first longitudinal screen section, whereby current induced in the electromagnetic shield by the magnetic field flows in the closed circuit path established by the first transverse screen element, the first longitudinal screen section, the second transverse screen element and the second longitudinal screen section (10c"), and opposing electromagnetic fields established by opposing currents in the first and second longitudinal screen sections (10c', 10c") substantially cancel each other.