Abstract: Methods and device for the electric welding of at least two sheets of multilayer structure (2,5), termed sandwich sheets, each including at least two metal sheets interconnected by a film of polymer. The method includes putting the inner faces (3a, 7a) of the sandwich sheets (2,5) into contact in a partial overlapping region, applying on the opposite faces (4a, 6a) of the sandwich sheets at least two rollers each having two parts and placed in confronting relation to each other in alignment with the overlapping region, supplying electric power to at least the second part of each roller (9,10), exerting a clamping force on the overlapping region of the sandwich sheets (2,5) using the rollers so as to bring the second part of each of the rollers into contact with the inner face of the confronting sandwich sheet and shifting the rollers (9,10) along the overlapping region.