To realize a structure for absorbing a thermal expansion difference between a metallic catalyst carrier and an outer cylinder without applying any stress to the metallic catalyst carrier or without increasing its manufacturing tolerance.

An exhaust emission control catalyst device is provided, which is installed in the exhaust gas passage of an internal combustion engine for controlling exhaust gas by a metallic carrier 3 housed in a metallic outer cylinder 1. In this case, a buffer material 11 made of a heat resisting wire net is disposed between the metallic carrier 3 and the metallic outer cylinder 1 and the buffer material 11, the metallic carrier 3 and the metallic outer cylinder 1 are connected to one another so as to be electrically conductive. At this time, the buffer material 11 disposed between the metallic carrier 3 and the outer cylinder 1 is compressed before its disposing and joining between the metallic carrier 3 of the buffer material 11 and the outer cylinder 1 or local joined parts are disposed so as not to be laid over each other in the axial direction of the outer cylinder 1. The exhaust emission control catalyst device thus constructed is applied to an electric heating type catalyst device, and in this case, the metallic carrier 3 is made conductive and the leakage of non-controlled exhaust gas is prevented by a retainer or an expanded diameter section provided in the outer cylinder.