Abstract: A brazed heat exchanger having a stack of heat exchanger plates, each with an inflow hole and an outflow hole, that are arranged such that closed and open flow ducts for different media alternate in a stack direction. In the open flow ducts are two endpieces with a hole whose edge extends around the inflow hole or around the outflow hole respectively. The endpieces are deformed metal sheets with corrugations that form ducts, The metal sheets include flow openings for the medium flowing through the open flow ducts. The hole edges are deformed and have a height approximately corresponding to a height of the open flow duct, and are arranged close to a rim hole of the inflow hole or of the outflow hole.