HEAT EXCHANGER

The invention relates to a heat exchanger (1), in particular an exhaust gas heat exchanger, comprising: - tubes (5) held at both ends in a tube sheet (3,4) for guiding a gaseous medium, - a housing (6) adjoining the tube sheets (3,4) and enclosing the tubes (5) for conducting a cooling medium, - at least one diffuser (9) adjoining the tube sheet (3,4) and/or the housing (6) on the outlet side or inlet side, which has a first flange (10) facing the housing (6) and a second flange (11) facing away from it. The essential feature of the invention is that the at least one diffuser (9) with the two flanges (10,11) is designed as a one-piece deep-drawn part.