Abstract: A heat exchanger according to some embodiments includes heat exchanger plates stacked one inside the other and each having a trough-shaped edge, flow ducts located between the heat exchanger plates for heat-exchanging media, feed ducts and discharge ducts, and an attachment plate having openings for feeding and discharging the media through the attachment plate. In some embodiments, a multipart attachment plate is provided, wherein a bottom heat exchanger plate lies on an attachment plate, and another overlying attachment plate has a cutout having an edge shaped to lie against the trough-shaped edge of the bottom heat exchanger plate.