A metallic carrier composed of an end face portion formed in at least one of the axial end portions of a honeycomb body and an outer circumferential reinforcing layer in which foils in a range from the outermost layer to a quarter of the total number of layers are joined together in the axial intermediate portion. Thus, the metallic carrier is flexible in expansion and shrinkage. Further, the honeycomb body and a jacket are joined to each other mainly at the outer circumference of the outer circumferential reinforcing layer of the honeycomb body, to reduce thermal stress developed between the honeycomb body and jacket while maintaining the strength against a high temperature, to thereby prevent the metallic carrier from being ruptured.