A cylinder head that has a built-in exhaust manifold of an engine, the cylinder head comprising: an outer coolant passage (23A, 23B) in which an engine coolant circulates and that is disposed along the manifold positioned at a side of an outer surface of the cylinder head; and an inner coolant passage (24A, 24B) whose shape is branched from the outer coolant passage and then joins, and that is disposed along the outer coolant passage and at an inner side of the cylinder head, wherein the outer coolant passage (23A, 23B) is disposed along a portion of the manifold and in a semicircular arc shape when seen from a top view of the engine, the portion being connected to an outer cylinder (#1, #4) positioned at the side of the outer surface of the engine, and the inner coolant passage (24A, 24B) is disposed along another portion of the manifold and in a semicircular arc shape and closer to an inside than the outer coolant passage when seen from the top view of the engine, the another portion being connected to an inner cylinder (#2, #3) positioned at an inner side of the engine, wherein the cylinder head further comprises a plurality of connection coolant passages (28A, 28B) that each connect the outer coolant passage (23A, 23B) and the inner coolant passage (24A, 24B) and are disposed adjacent to bifurcated portions (16, 17) at which branch pipes of the manifold join; the bifurcated portions (16, 17) include first bifurcated portions each sandwiched by middle passages positioned at an intermediate portion of the manifold and a second bifurcated portion sandwiched by large passages each formed by joining the middle passages; and the connection coolant passages (28A, 28B) are disposed at positions overlapping the first bifurcated portions and the second bifurcated portion when seen from the top view of the engine. an outer coolant passage (23A, 23B) in which an engine coolant circulates and that is disposed along the manifold positioned at a side of an outer surface of the cylinder head; and an inner coolant passage (24A, 24B) whose shape is branched from the outer coolant passage and then joins, and that is disposed along the outer coolant passage and at an inner side of the cylinder head, wherein the outer coolant passage (23A, 23B) is disposed along a portion of the manifold and in a semicircular arc shape when seen from a top view of the engine, the portion being connected to an outer cylinder (#1, #4) positioned at the side of the outer surface of the engine, and the inner coolant passage (24A, 24B) is disposed along another portion of the manifold and in a semicircular arc shape and closer to an inside than the outer coolant passage when seen from the top view of the engine, the another portion being connected to an inner cylinder (#2, #3) positioned at an inner side of the engine, wherein the cylinder head further comprises a plurality of connection coolant passages (28A, 28B) that each connect the outer coolant passage (23A, 23B) and the inner coolant passage (24A, 24B) and are disposed adjacent to bifurcated portions (16, 17) at which branch pipes of the manifold join; the bifurcated portions (16, 17) include first bifurcated portions each sandwiched by middle passages positioned at an intermediate portion of the manifold and a second bifurcated portion sandwiched by large passages each formed by joining the middle passages; and the connection coolant passages (28A, 28B) are disposed at positions overlapping the first bifurcated portions and the second bifurcated portion when seen from the top view of the engine.