Exhaust system for an internal combustion engine, comprising an exhaust gas flow duct, through which exhaust gas can flow in an exhaust gas main flow direction, and a reactant injection device for injecting reactant in a reactant injection area of the exhaust gas flow duct in a reactant main injection direction, wherein the reactant main injection direction and the exhaust gas main flow direction in the reactant injection area are not parallel and not at right angles to one another, wherein the reactant collecting arrangement comprises a plurality of reactant collecting surface elements (30; 30a, 30b, 30c, 30d), wherein each reactant collecting surface element (30; 30a, 30b, 30c, 30d) has a U-shaped cross-section and, on a side facing the reactant injection device transversely to the main exhaust gas flow direction, a reactant collection surface which can be wetted with reactant injected by means of the reactant injection device, wherein at least one U-shaped reactant collecting surface element (30; 30a; 30b, 30c) is fixed to a wall of an exhaust gas flow pipe in the region of free ends of its U-legs, characterized in that - at least two reactant collecting surface elements (30a, 30b, 30c, 30d) are arranged nested one inside the other, wherein each U-shaped reactant collecting surface element (30a; 30b, 30c) is fixed to the wall of the exhaust gas flow pipe in the region of free ends of its respective U-legs, or wherein one of the U-shaped reactant collecting surface elements is fixed to the wall of the exhaust gas flow pipe in the region of free ends of its U-legs and reactant collecting surface elements (30b, 30c, 30d) are arranged transversely to the main exhaust gas flow direction at a distance from one another inside the U-contour of the reactant collecting surface element fixed to the wall and are connected to the reactant collecting surface element fixed to the wall in the region of their U-legs, or - in that one of the reactant collecting surface elements is fixed with its U-legs to the wall of the exhaust gas flow pipe and that a further reactant collecting surface element is fixed in the region of the free ends of its U-legs in the region of the reactant collection surface of the reactant collecting surface element fixed to the wall of the exhaust gas flow pipe. - at least two reactant collecting surface elements (30a, 30b, 30c, 30d) are arranged nested one inside the other, wherein each U-shaped reactant collecting surface element (30a; 30b, 30c) is fixed to the wall of the exhaust gas flow pipe in the region of free ends of its respective U-legs, or wherein one of the U-shaped reactant collecting surface elements is fixed to the wall of the exhaust gas flow pipe in the region of free ends of its U-legs and reactant collecting surface elements (30b, 30c, 30d) are arranged transversely to the main exhaust gas flow direction at a distance from one another inside the U-contour of the reactant collecting surface element fixed to the wall and are connected to the reactant collecting surface element fixed to the wall in the region of their U-legs, or - in that one of the reactant collecting surface elements is fixed with its U-legs to the wall of the exhaust gas flow pipe and that a further reactant collecting surface element is fixed in the region of the free ends of its U-legs in the region of the reactant collection surface of the reactant collecting surface element fixed to the wall of the exhaust gas flow pipe.