NOVELTY - The device (1) for an exhaust gas system of an internal combustion engine, comprises a housing (4) having a longitudinal axis, a first front side (6) and a second front side (7) and including an inlet and an outlet for the exhaust gas and an inlet and an outlet for the cooling medium, a catalyst carrier body flowable by exhaust gas and arranged in the housing, where the catalyst carrier body has outer circumferential surface and inner circumferential surface, and tube elements (17) arranged downstream to the catalyst carrier body, where the tube elements have inner sides and outer sides.    USE - Device for an exhaust gas system of an internal combustion engine, which is useful in a motor car.    ADVANTAGE - The device is compact, and can be simply structured with high efficiency.    DETAILED DESCRIPTION - The device (1) for an exhaust gas system of an internal combustion engine, comprises a housing (4) having a longitudinal axis, a first front side (6) and a second front side (7) and including an inlet and an outlet for the exhaust gas and an inlet and an outlet for the cooling medium, a catalyst carrier body flowable by exhaust gas and arranged in the housing, where the catalyst carrier body has an outer circumferential surface and an inner circumferential surface, and tube elements (17) arranged downstream to the catalyst carrier body, where the tube elements have inner sides and outer sides. The exhaust gas enters into the housing over the first front side, radially flows through the catalyst carrier body over the inner circumferential surface to the outer circumferential surface and exits over the second front side. The tub elements are arranged parallel to the longitudinal axis along the outer circumferential surface, where the outer sides are impacted with exhaust gas and the inner sides are impacted by the cooling medium. Thermoelectric elements are arranged between the outer side and the inner side of the tube elements, are formed in the tube elements in a disk-like manner and are stacked to each other. The outer sides and the inner sides of the tube elements and the thermoelectric elements arranged between the sides of the tube elements are positively connected with one another. The tube elements have a first end and a second end and are electrically contacted by a tube element plate. The tube elements are incorporated in the tube element plate at the first front side and at the second front side, where the inlet is arranged at the second front side and the outlet is arranged at the first front side. The tube element plate has openings for the reception of the tube elements, and channels for flow-technically connecting the inlet and/or the outlet for the cooling medium with the tube elements. First contacts are provided to connect the first end of the tube elements electrically conductively with a first electrical conductor. Second contacts are provided to connect the second end of the tube elements with a second electrical conductor. The second contacts are implemented against the first contacts in an electrically insulating manner.    DESCRIPTION OF DRAWING(S) - The figure shows a schematic representation of a device with a tube element.    Device (1)    Housing (4)    First front side (6)    Second front side (7)    Tube elements. (17)