Abstract: In a method of manufacturing a plate heat exchanger individual plates are connected to pairs such that the individual plates are parallel to and spaced from one another by edge portions with a common edge. The pairs are combined to a plate stack such that the common edges are parallel. A sealing strip, having a slotted end face with parallel slots, is positioned at the end of the plate stack such that the common edges are received in the slots and the edge portions abut the slotted end face and such that the end of the plate stack projects slightly past the outer surface of the sealing strip perpendicular to the slotted end face. The sealing strip is welded to the common edges by using at least a portion of the material of the plate stack end projecting past the outer surface. The edge portions are welded to the outer surface of the sealing strip by using exclusively the material of the plate stack projecting past the outer surface.