An EGR cooler includes a tube assembly formed by stacking a plurality of tubes in which exhaust gas flows and a cover plate having a mounting portion formed concavely to mount the tube assembly thereon. A baffle is mounted at the tube assembly and adjusts flow of coolant inflow from a cylinder block. An inlet cover is installed on a first side of an outer surface of the cover plate to supply the exhaust gas to each tube and an outlet cover is installed on a second side of outer surface of the cover plate to exhaust the exhaust gas from each tube. At least one coolant passage in which the coolant flows is formed between the plurality of tubes.