Abstract: A heat exchanger has a heat exchanging element with a first terminal plate closing the heat exchanging element on one of its sides and with at least one opening provided with a socket for fluids for the heat exchanger element. At least a first gasket carrier plate has a first lateral face arranged adjacent to the first terminal plate and an opposite second lateral face. The first gasket carrier plate has at least one passage opening leading from the first to the second lateral face for taking up at least one socket of the first terminal plate. A first sealing element is provided between the first terminal plate and the first gasket carrier plate. A second sealing element is provided adjacent to the second lateral face. The at least one socket of the first terminal plate is bulged outwardly to adjoin to the second sealing element at least in sections.