<p>A cylinder head includes a cylinder head body provided with intake and exhaust ports opened toward a combustion chamber and capable of being closed by valves, the intake and exhaust ports being separated from each other in a circumferential direction around a cylinder central axis. An opening section of at least one of the intake and exhaust ports facing the combustion chamber is provided with a seat surface centered on a valve axis and a tapered surface disposed closer to the combustion chamber than the seat surface, the tapered surface being gradually increased in diameter as close to the combustion chamber. A central axis of the tapered surface is disposed eccentrically from the valve axis toward the cylinder central axis.</p>
