To simply and easily process an oil path of a timing variable mechanism and a lift variable mechanism on an intake side and an exhaust side of a DOHC engine of a tappet type multi-cylinder series.

A cam holder 101 comprising a separate lower member 104 and a cap member 105 is arranged on a cylinder head 1, and intake side and exhaust side lift variable oil galleries 111, 112 are arranged at a top center of the cylinder head 1, and cam journal lubricating oil galleries 113, 114 are arranged on right and left sides thereof. Intake side and exhaust side timing variable hydraulic control valves 121, 122 are arranged on the top face of a cam holder 101 at frontmost part, and a lift variable hydraulic control valve 123 is arranged between them to form each oil path by drilling.