An exhaust purification apparatus for an engine comprises a selective reduction-type NOx catalyst that is interposed in an exhaust passage of the engine and selectively reduces NOx contained in exhaust gas of the engine, an EGR device that recirculates exhaust gas of the engine to an intake side of the engine, an exhaust-purification-efficiency estimation unit that estimates exhaust purification efficiency of the NOx catalyst with respect to NOx, a target-exhaust-purification-efficiency calculation unit that calculates target exhaust purification efficiency with respect to NOx on the basis of an operational state of the engine, and a control unit that controls the EGR device to compensate a decrease amount of the estimated exhaust purification efficiency to the target exhaust purification efficiency.