The invention relates to an electromagnetic pulse-welding device for joining a metal sheet to a metal part, consisting of an electric energy source which is connected to a coil by means of a current conductor, the active part of said coil being in the direct proximity of the metal sheet, said metal sheet being at a distance from the metal part. The passive part of the coil has a larger cross-section than the active part and said active part borders on one part of the surface in a positive fit, to a cooling insulator, the material having a relatively high thermal conductivity and a relatively low magnetic and electric conductivity compared to the material of the coil.