A heating device for the electromagnetic induction heating of a metal strip traveling in a specified direction. The device includes at least one electric coil arranged opposite at least one of the large surfaces of the strip so as to heat the latter by transverse magnetic flux induction, each coil being associated with at least one magnetic circuit. Each circuit is divided into a plurality of magnetically independent bars arranged parallel to the direction of travel of the strip. The bars may moved toward or away one another thereby adapting to the width of the strip and distributing the magnetic flux across the width of the strip.