Described herein is an exhaust manifold (1) comprising suction opening (2), a gas extraction chamber (3), an intermediate space (9), a gas collection chamber (5) and a suction line (4). A flow-impeding structure may be present within the intermediate space (9). The flow impeding structure may exert a flow resistance on the gas flow which is greater in a central zone (Z) than in edge zones (R) of the intermediate space (9), causing gas to flow into the suction opening (2) at a substantially uniform gas flow speed across the cross section of the suction opening (2).