EXHAUST PURIFICATION APPARATUS

An object of the invention is to make it possible to introduce exhaust gas 3 into a post-treatment unit such as selective reduction catalyst 6 through turnabout, with distribution of flow of the exhaust gas 3 being uniformized. Disclosed is an exhaust emission control device with a selective reduction catalyst 6 (post-treatment unit) for depuration of the exhaust gas 3 through passing therethrough being arranged in an exhaust system, a layout being applied which introduces the exhaust gas 3 into the selective reduction catalyst 6 through turnabout. An introductory part 14 is provided which encircles an inlet end of the selective reduction catalyst 6 and guides the exhaust gas 3 through the exhaust inlet port 13 from a direction substantially perpendicular to an axis of the selective reduction catalyst 6. The introduction part 14 is formed with a depression 15 (first depression) cambered away from the inlet end of the selective reduction catalyst 6 and approaching toward the inlet end of the selective reduction catalyst 6 as it extends away from the exhaust inlet port 13 into an introduction direction of the exhaust gas 3.