Provided are an exhaust purification device for a diesel engine, and an exhaust purification method that utilizes this exhaust purification device enabling effective utilization of exhaust gas heat and allowing reduction in the size of the device, by virtue of the design of the layout of each post-processing units. An exhaust purification device 17 has an oxidation catalyst 19 that is disposed in an exhaust passage 7 of a diesel engine 1 and purifies CO and HC in exhaust gas; a urea injection nozzle 22 that is disposed downstream of the oxidation catalyst 19 and generates ammonia through atomization of urea water into the exhaust gas; a turbine 13 of a turbocharger 9, this turbine being disposed downstream of the urea injection nozzle 22 and accelerating decomposition of urea through agitation of the atomized urea water; a DPF 20 that is disposed downstream of the turbine 13 and traps PM in the exhaust gas; and a selective reduction catalyst 23 that is disposed downstream of the DPF 20 and detoxifies NOx in t
