An engine apparatus comprising: an engine comprising: a cylinder head comprising a first side; an exhaust manifold on the first side of the cylinder head; and an output shaft comprising a core; an exhaust gas purification device comprising an exhaust gas inlet side and an exhaust gas outlet side, the exhaust gas purification device being mounted above the cylinder head to extend along the core of the output shaft of the engine, the exhaust gas purification device being configured to purify exhaust gas from the exhaust manifold; an outlet side bracket configured to couple the exhaust gas outlet side of the exhaust gas purification device to the cylinder head; and an inlet side bracket configured to couple the exhaust gas inlet side of the exhaust gas purification device to the cylinder head, the engine apparatus further comprising a cylinder block comprising end surfaces, the end surfaces of the cylinder block being secured to a traveling body of a traveling vehicle via a front engine mount; a flywheel disposed on one of the end surfaces of the cylinder block intersecting the core of the engine output shaft; and a flywheel housing comprising a width and a height and covering the flywheel, the flywheel housing being configured such that the width is narrower than the height, wherein the engine apparatus is configured to be covered with a hood, wherein the inlet side bracket comprising: a first bracket configured to be secured to a surface of the cylinder head intersecting the core of the output shaft; a second bracket comprising a proximal end portion and a distal end portion, the proximal end portion configured to be coupled to an upper end of the first bracket, the distal end portion being bent sideways with respect to the proximal end portion; and a third bracket configured to be coupled to an end surface of the exhaust gas purification device and the distal end portion of the second bracket, and wherein the flywheel housing comprises an outline in which left and right parts of a circle are cut off and in which a seat projects from an upper section, and the seat on the upper section is configured to be coupled to the traveling body via a rear engine mount. an engine comprising: a cylinder head comprising a first side; an exhaust manifold on the first side of the cylinder head; and an output shaft comprising a core; a cylinder head comprising a first side; an exhaust manifold on the first side of the cylinder head; and an output shaft comprising a core; an exhaust gas purification device comprising an exhaust gas inlet side and an exhaust gas outlet side, the exhaust gas purification device being mounted above the cylinder head to extend along the core of the output shaft of the engine, the exhaust gas purification device being configured to purify exhaust gas from the exhaust manifold; an outlet side bracket configured to couple the exhaust gas outlet side of the exhaust gas purification device to the cylinder head; and an inlet side bracket configured to couple the exhaust gas inlet side of the exhaust gas purification device to the cylinder head, a flywheel disposed on one of the end surfaces of the cylinder block intersecting the core of the engine output shaft; and a flywheel housing comprising a width and a height and covering the flywheel, the flywheel housing being configured such that the width is narrower than the height, wherein the engine apparatus is configured to be covered with a hood, wherein the inlet side bracket comprising: a first bracket configured to be secured to a surface of the cylinder head intersecting the core of the output shaft; a second bracket comprising a proximal end portion and a distal end portion, the proximal end portion configured to be coupled to an upper end of the first bracket, the distal end portion being bent sideways with respect to the proximal end portion; and a third bracket configured to be coupled to an end surface of the exhaust gas purification device and the distal end portion of the second bracket, and wherein the flywheel housing comprises an outline in which left and right parts of a circle are cut off and in which a seat projects from an upper section, and the seat on the upper section is configured to be coupled to the traveling body via a rear engine mount. a first bracket configured to be secured to a surface of the cylinder head intersecting the core of the output shaft; a second bracket comprising a proximal end portion and a distal end portion, the proximal end portion configured to be coupled to an upper end of the first bracket, the distal end portion being bent sideways with respect to the proximal end portion; and a third bracket configured to be coupled to an end surface of the exhaust gas purification device and the distal end portion of the second bracket, and wherein the flywheel housing comprises an outline in which left and right parts of a circle are cut off and in which a seat projects from an upper section, and the seat on the upper section is configured to be coupled to the traveling body via a rear engine mount.