The invention relates to a method for joining at least one sandwich sheet to at least one functional element made of metal, wherein the at least one sandwich sheet has two metallic outer layers and a thermoplastic layer arranged between the metallic outer layers, wherein at least the region to be joined of the at least one sandwich sheet is heated in such a manner that the thermoplastic layer softens, the plastic layer is pushed out of the joining region by the outer layers being pressed together, and the outer layers of the at least one sandwich sheet are joined, in particular welded, to the functional element by an electric current flow between a first and a second electrode.