An exhaust purification apparatus for an engine has a first casing (17) that is interposed in an exhaust path (13); a second casing (23) that is set downstream of the first casing (17) and contains an exhaust purification device (24); a connecting pipe (22, 41, 51) that connects the first casing and the second casing (23) to each other and includes an insertion portion that is inserted in the first casing (17); and an injection nozzle (27, 52) that has a tip end inserted in the connecting pipe (22, 41, 51) and injects an auxiliary agent from the tip end. The insertion portion of the connecting pipe (22, 41, 51) is provided with a plurality of through-holes (22a, 41a, 41b, 51a) connecting the inside and the outside of the connecting pipe (22, 41, 51), so that the exhaust gas contained in the first casing (17) is introduced into the connecting pipe (22, 41, 51) through the through-holes and guided towards the second casing (23).