To efficiently perform deposit removal in an EGR flow passage by executing the deposit removal in a high-load state of an engine, thereby securing a larger flow rate of exhaust gas flowing through the EGR flow passage than in a low-road state of the engine.

The apparatus includes: the EGR flow passage 4; an EGR gas flow adjusting valve 5; an EGR cooler 6; a cooling water circulation path 7; a cooling water flow adjusting valve 8; and a control device 10 which causes a part of exhaust gas to flow to the EGR flow passage 4 by the EGR gas flow adjusting valve 5 when the temperature of cooling water is equal to or higher than a predetermined temperature, and executes the deposit removal when the engine is determined to be in the high-load state with the exhaust gas flowing through the EGR flow passage 4 and also to be at a deposit removal execution timing.