To provide a metal support unit for catalyst, which is used in a catalyst converter adapted to be installed in an automobile, for purifying exhaust gas, and the manufacture thereof, so as to surely prevent cracking and breaking of a planar plate and to make the contact force between the planer plate and a corrugated plate, uniform at any position.

In a metal support unit for catalyst in which a metal support 25 composed of metal planar plates 27 and corrugated plates 29 alaternately stacked one upon another, is accommodated in a metal outer cylinder 21, the stack of the planer plates 27 and the corrugated plates 29 of the metal support 25 has a U-like shape having U-like opening ends 27a, 29a which are accommodated in the outer cylinder 21, and the planer plates 27 and the corrugated plates are subjected to diffusion bonding, and are joined to the inner periphery of the outer cylinder 21.