An engine device comprising: a cylinder head provided with a plurality of intake fluid passages for taking fresh air into a plurality of intake ports and a plurality of exhaust fluid passages for emitting an exhaust gas from a plurality of exhaust ports, wherein an intake manifold which aggregates the plurality of intake fluid passages is disposed in one of left and right side portions of the cylinder head wherein the left and right side portions of the cylinder head are opposite side portions parallel to a crankshaft, the engine device further comprises: an exhaust manifold in communication with the exhaust fluid passages; an EGR device configured to circulate, as EGR gas, a portion of exhaust gas exhausted from the exhaust manifold to the intake manifold; and an EGR cooler configured to cool the EGR gas, wherein the cylinder head is configured such that the exhaust manifold is coupled to a second surface of the cylinder head which is opposite to a first surface where the intake manifold is disposed, the EGR cooler is coupled to a third surface of the cylinder head which is adjacent to the first and second surfaces, and coupling bases (33, 34) to which the EGR cooler is coupled are provided so as to protrude from the third surface of the cylinder head, and wherein the coupling bases (33, 34) on the third surface are provided therein with EGR gas fluid passages (31, 32) and coolant passages (38, 39); wherein the EGR device is coupled to the intake manifold; characterized in that the coupling bases (33, 34) form a pair of the coupling bases (33, 34), the pair of the coupling bases (33, 34) is formed by left and right edges, the left and right edges are located on the left side portion and right side portion of the third surface of the cylinder head, respectively, wherein the left and right edges are disposed on an exhaust manifold side of the third surface and on an intake manifold side of the third surface, respectively, one of the coupling bases (33, 34) has a downstream EGR gas relay fluid passage through which an EGR gas fluid passage of the EGR device communicates with an EGR gas fluid passage of the EGR cooler, and the other of the coupling bases (33, 34) has an upstream EGR gas relay fluid passage through which an EGR gas fluid passage of the exhaust manifold communicates with the EGR gas fluid passage of the EGR cooler, the EGR cooler includes a pair of left and right flange portions (92, 93) and one of the flange portions has a coolant outlet and an EGR gas inlet, while the other flange portion has a coolant inlet and an EGR gas outlet, and the left and right flange portions (92, 93) are connected to the coupling bases (33, 34) of the cylinder head. wherein an intake manifold which aggregates the plurality of intake fluid passages is disposed in one of left and right side portions of the cylinder head wherein the left and right side portions of the cylinder head are opposite side portions parallel to a crankshaft, the engine device further comprises: an exhaust manifold in communication with the exhaust fluid passages; an EGR device configured to circulate, as EGR gas, a portion of exhaust gas exhausted from the exhaust manifold to the intake manifold; and an EGR cooler configured to cool the EGR gas, wherein the cylinder head is configured such that the exhaust manifold is coupled to a second surface of the cylinder head which is opposite to a first surface where the intake manifold is disposed, the EGR cooler is coupled to a third surface of the cylinder head which is adjacent to the first and second surfaces, and coupling bases (33, 34) to which the EGR cooler is coupled are provided so as to protrude from the third surface of the cylinder head, and wherein the coupling bases (33, 34) on the third surface are provided therein with EGR gas fluid passages (31, 32) and coolant passages (38, 39); wherein the EGR device is coupled to the intake manifold; characterized in that the coupling bases (33, 34) form a pair of the coupling bases (33, 34), the pair of the coupling bases (33, 34) is formed by left and right edges, the left and right edges are located on the left side portion and right side portion of the third surface of the cylinder head, respectively, wherein the left and right edges are disposed on an exhaust manifold side of the third surface and on an intake manifold side of the third surface, respectively, one of the coupling bases (33, 34) has a downstream EGR gas relay fluid passage through which an EGR gas fluid passage of the EGR device communicates with an EGR gas fluid passage of the EGR cooler, and the other of the coupling bases (33, 34) has an upstream EGR gas relay fluid passage through which an EGR gas fluid passage of the exhaust manifold communicates with the EGR gas fluid passage of the EGR cooler, the EGR cooler includes a pair of left and right flange portions (92, 93) and one of the flange portions has a coolant outlet and an EGR gas inlet, while the other flange portion has a coolant inlet and an EGR gas outlet, and the left and right flange portions (92, 93) are connected to the coupling bases (33, 34) of the cylinder head.