A cylinder head cover covers a cylinder head of an internal combustion engine. The engine has a variable valve actuation mechanism and a control valve for controlling supply and drainage of hydraulic oil to and from the variable valve actuation mechanism. The cylinder head cover includes a cover main body fixed to the cylinder head and a valve case to which the control valve is attached. The valve case is caused to contact a side of the cover main body that corresponds to the cylinder head. Therefore, the cylinder head cover maintains a firm attachment of the valve case to the cylinder head.