EXHAUST GAS EMISSION CONTROL DEVICE OF INTERNAL COMBUSTION ENGINE

PROBLEM TO BE SOLVED: To secure a distance for mixing by making exhaust gas and urea water flow in the circumferential direction, to downsize a length in the direction of an exhaust system passage, to reduce the thickness of the entire device, and to improve mounting property of an exhaust gas emission control device, assembling property to a vehicle and the like, by forming an exhaust gas distribution passage for turning the exhaust gas flow in the circumferential direction around the axis of the exhaust gas distribution system on the upstream side of a catalyst device of the exhaust system passage, and providing a mixing promotion chamber for promoting the mixing of exhaust gas with urea water.SOLUTION: An exhaust gas emission control device includes: a selective reduction catalyst 8 which is provided in an exhaust system passage of an engine 1 to clean exhaust gas by supplying additive; a mixing promotion chamber 7(8) which is provided on the upstream side of the selective reduction catalyst 8 to form an exhaust gas distribution passage 79 (85) for turning the exhaust gas flow along the circumferential direction around the axis of the exhaust passage and to promote the mixing of exhaust gas with the additive; and a urea water jetting nozzle 9 for jetting the additive to the exhaust gas distribution passage 79 in the vicinity of an exhaust gas introduction hole 76 of the exhaust gas distribution passage 79.