An internal combustion engine with an EGR device, a body of the internal combustion engine being provided with an exhaust passage portion (9, 10) into which an exhaust gas from the body is introduced, the body including: a cylinder block; a cylinder head attached to an upper portion of the cylinder block; and a cylinder head cover (5, 25) attached to an upper portion of the cylinder head, the cylinder head cover (5, 25) including: an exhaust side wall located on one of both sides of the body where the exhaust passage portion (9, 10) is installed; an intake side wall located on the other side of the body, being away from the exhaust side wall; and a connection wall extending between the exhaust side wall and the intake side wall, to connect the exhaust side wall and the intake side wall to each other, the EGR device comprising: an EGR passage portion (12, 13, 26, 15) branching from the exhaust passage portion (9, 10) to circulate, as an EGR gas, a part of the exhaust gas in the exhaust passage portion (9, 10) into the body; and an EGR valve to adjust a flow rate at which the EGR gas flows through the EGR passage portion (12, 13, 26, 15), wherein the cylinder head cover (5, 25) includes a head cover EGR passage portion that constitutes a part of the EGR passage portion (12, 13, 26, 15), the head cover EGR passage portion includes a through-hole that extends from an exhaust-side open portion to an intake-side open portion, the exhaust-side open portion being formed at the exhaust side wall of the cylinder head cover (5, 25), the intake-side open portion being formed at the intake side wall thereof, and the EGR valve is attached to the exhaust side wall so as to cover the exhaust-side open portion, the EGR valve being fastened to a first fastening portion and a second fastening portion, the first fastening portion being provided at an intersection where the exhaust side wall and the connection wall intersect, the second fastening portion being provided at the exhaust side wall. the body including: a cylinder block; a cylinder head attached to an upper portion of the cylinder block; and a cylinder head cover (5, 25) attached to an upper portion of the cylinder head, the cylinder head cover (5, 25) including: an exhaust side wall located on one of both sides of the body where the exhaust passage portion (9, 10) is installed; an intake side wall located on the other side of the body, being away from the exhaust side wall; and a connection wall extending between the exhaust side wall and the intake side wall, to connect the exhaust side wall and the intake side wall to each other, the EGR device comprising: an EGR passage portion (12, 13, 26, 15) branching from the exhaust passage portion (9, 10) to circulate, as an EGR gas, a part of the exhaust gas in the exhaust passage portion (9, 10) into the body; and an EGR valve to adjust a flow rate at which the EGR gas flows through the EGR passage portion (12, 13, 26, 15), wherein the cylinder head cover (5, 25) includes a head cover EGR passage portion that constitutes a part of the EGR passage portion (12, 13, 26, 15), the head cover EGR passage portion includes a through-hole that extends from an exhaust-side open portion to an intake-side open portion, the exhaust-side open portion being formed at the exhaust side wall of the cylinder head cover (5, 25), the intake-side open portion being formed at the intake side wall thereof, and the EGR valve is attached to the exhaust side wall so as to cover the exhaust-side open portion, the EGR valve being fastened to a first fastening portion and a second fastening portion, the first fastening portion being provided at an intersection where the exhaust side wall and the connection wall intersect, the second fastening portion being provided at the exhaust side wall. an EGR passage portion (12, 13, 26, 15) branching from the exhaust passage portion (9, 10) to circulate, as an EGR gas, a part of the exhaust gas in the exhaust passage portion (9, 10) into the body; and an EGR valve to adjust a flow rate at which the EGR gas flows through the EGR passage portion (12, 13, 26, 15), wherein the cylinder head cover (5, 25) includes a head cover EGR passage portion that constitutes a part of the EGR passage portion (12, 13, 26, 15), the head cover EGR passage portion includes a through-hole that extends from an exhaust-side open portion to an intake-side open portion, the exhaust-side open portion being formed at the exhaust side wall of the cylinder head cover (5, 25), the intake-side open portion being formed at the intake side wall thereof, and the EGR valve is attached to the exhaust side wall so as to cover the exhaust-side open portion, the EGR valve being fastened to a first fastening portion and a second fastening portion, the first fastening portion being provided at an intersection where the exhaust side wall and the connection wall intersect, the second fastening portion being provided at the exhaust side wall.