To create a heat exchanger which provides for a high temperature compensation between the media, can at the same time be produced at low cost and satisfies the thermal stresses, it is proposed that the heat exchanger has a first distribution chamber (5) which is connected with a second distribution chamber (7) by means of tubes (22, 6) for the passage of hot medium (2), the tubes (6) extending through the inlet region (11) of the cooling medium (3) and an outer chamber (12), that lateral ports (9) introduce the cooling medium (3) into an inlet region (10) which is adjoined by an inner chamber (11) defined by a sealing plate (16) for flow deflection of the cooling medium (3), that the sealing plate (16) guides the cooling medium (3) from the inner chamber (11) into the outer chamber (12), the outer chamber (12) enclosing the inner chamber (11), and this outer chamber (11) is provided with ports (18) for discharging the cooling medium (3).