This invention relates to an exhaust treatment device for an exhaust system of an internal combustion engine, particularly in a motor vehicle. The device comprises a housing in which at least one exhaust treatment insert is arranged, and which is composed of at least two housing sections at least one of which consists of a ferritic material and at least another of which consists of an austenitic material. In order to increase the thermal resistance of the device at least one ferritic housing section is secured to at least one austenitic housing section by means of a connection, wherein this connection consists of a material whose coefficient of thermal expansion lies between the coefficients of thermal expansion of the ferritic material and of the austenitic material.