An internal combustion engine with an EGR device, the internal combustion engine including: a body mounted on a vehicle, in which: a cylinder head is attached to an upper portion of a cylinder block; a cylinder head cover (5, 25) is attached to an upper portion of the cylinder head; and a crankshaft extends along a vehicle left-right direction, and an exhaust passage portion (9, 10) into which an exhaust gas from the body is introduced, the exhaust passage portion (9, 10) being attached to an exhaust side wall of the cylinder head, the exhaust passage portion (9, 10) including an exhaust cleaning device extending along a vehicle up-down direction, the EGR device comprising: an EGR passage portion (12, 13, 26, 15) branching from the exhaust cleaning device to circulate, as EGR gas, a part of the exhaust gas in the exhaust passage portion (9, 10) into the body; an EGR cooler with an EGR cooler body formed in a rectangular parallelepiped shape, the EGR cooler body extending in a vehicle up-down direction along the exhaust cleaning device, the EGR cooler constituting a part of the EGR passage portion (12, 13, 26, 15); and a coolant piping (52, 53) to allow a coolant circulating in the body to flow into the EGR cooler to thereby cool the EGR gas flowing through the EGR cooler, wherein the EGR cooler body includes: a first side wall facing the exhaust cleaning device; a second side wall located on the opposite side from the exhaust cleaning device with respect to the first side wall; and a third side wall and a fourth side wall both of which interconnect end portions in a width direction of the first side wall and the second side wall, and the coolant piping (52, 53) is connected to the second side wall. a body mounted on a vehicle, in which: a cylinder head is attached to an upper portion of a cylinder block; a cylinder head cover (5, 25) is attached to an upper portion of the cylinder head; and a crankshaft extends along a vehicle left-right direction, and a cylinder head is attached to an upper portion of a cylinder block; a cylinder head cover (5, 25) is attached to an upper portion of the cylinder head; and a crankshaft extends along a vehicle left-right direction, and an exhaust passage portion (9, 10) into which an exhaust gas from the body is introduced, the exhaust passage portion (9, 10) being attached to an exhaust side wall of the cylinder head, the exhaust passage portion (9, 10) including an exhaust cleaning device extending along a vehicle up-down direction, the EGR device comprising: an EGR passage portion (12, 13, 26, 15) branching from the exhaust cleaning device to circulate, as EGR gas, a part of the exhaust gas in the exhaust passage portion (9, 10) into the body; an EGR cooler with an EGR cooler body formed in a rectangular parallelepiped shape, the EGR cooler body extending in a vehicle up-down direction along the exhaust cleaning device, the EGR cooler constituting a part of the EGR passage portion (12, 13, 26, 15); and a coolant piping (52, 53) to allow a coolant circulating in the body to flow into the EGR cooler to thereby cool the EGR gas flowing through the EGR cooler, wherein the EGR cooler body includes: a first side wall facing the exhaust cleaning device; a second side wall located on the opposite side from the exhaust cleaning device with respect to the first side wall; and a third side wall and a fourth side wall both of which interconnect end portions in a width direction of the first side wall and the second side wall, and the coolant piping (52, 53) is connected to the second side wall. an EGR passage portion (12, 13, 26, 15) branching from the exhaust cleaning device to circulate, as EGR gas, a part of the exhaust gas in the exhaust passage portion (9, 10) into the body; an EGR cooler with an EGR cooler body formed in a rectangular parallelepiped shape, the EGR cooler body extending in a vehicle up-down direction along the exhaust cleaning device, the EGR cooler constituting a part of the EGR passage portion (12, 13, 26, 15); and a coolant piping (52, 53) to allow a coolant circulating in the body to flow into the EGR cooler to thereby cool the EGR gas flowing through the EGR cooler, wherein the EGR cooler body includes: a first side wall facing the exhaust cleaning device; a second side wall located on the opposite side from the exhaust cleaning device with respect to the first side wall; and a third side wall and a fourth side wall both of which interconnect end portions in a width direction of the first side wall and the second side wall, and a first side wall facing the exhaust cleaning device; a second side wall located on the opposite side from the exhaust cleaning device with respect to the first side wall; and a third side wall and a fourth side wall both of which interconnect end portions in a width direction of the first side wall and the second side wall, and the coolant piping (52, 53) is connected to the second side wall.