Cylinder head for use in an internal combustion engine

In a cylinder head 1 has boss portions 8 for head bolts 11 which are formed inside of both sides of the cylinder head 1, and a discharge/intake port 5 which extends from an intermediate portion 15a of a lower-surface deck 15 that is in contact with a gasket 9. In this cylinder head 1, ribs 16 are connected and supported from an upper portion 8a of the boss portions 8 toward a lower portion 5a of the intake port 5.