An exhaust catalytic converter unit (10) for a gas catalytic converter, a plurality of the catalytic converter module 11, respectively, of the catalytic converter module (11) is a ceramic catalyst body 13 and the ceramic catalyst body (13 which is perfused by the exhaust gas ) each of the ceramic catalyst body (13, further comprising a metal housing (12)) is that a plurality of the catalytic converter module (11 will) surrounded by a metallic housing at a particular section is accommodated in each of the metal housing 12, .; A support structure (12) for a plurality of the catalytic converter module 11, the catalytic converter module 11 has a of the support structure 12 will be fastened to the support structure 14 via these metal housing 12 . The support structure 14 has a catalytic converter module 11, a plurality of the opening-plate-shaped base body 15 and the opening 16 so as to protrude on the plate-shaped basic body having a 16 to accommodate in each case including the projection 17 surrounded by the frame, and the projection is formed in the first fastening flange (18) projecting to the outside for the openings 16 in each case on the side towards the away from the plate-like body 15 do. A metal housing 12 of the catalytic converter module 11, at this time be inserted into a collar projecting to the outside, in particular a catalytic converter module 11 the opening 16 of the support structure 14 relative to the housing (12) It has a collar 19 which is placed on the first fastening flange (18) of the projection 17 surrounds the opening 16 at one end. Each of the catalytic converter module 11 via the second via a fastening flange 21 or separate the second fastening flange is provided by the collar 19 of the metal housing 12 of each of the catalytic converter module (11) and through the at least one detachable fastening means interacting with fastening flanges surrounding the openings 16 for receiving each of the catalytic converter module (11) is fastened to the first fastening flange 18 of the projection 17.