A portable 4-cycle engine with a configuration which allows cooling air to flow in the direction of the crankshaft relative to a cylinder head on a cylinder, and a portable machine equipped with this engine, are provided, respectively. In such an engine, the cylinder is separated from the cylinder head including a combustion chamber formed at the cylinder side therein. The engine further comprises a valve train area formed in the cylinder head at the downwind side of the cooling air, and a plurality of vertical fins protruding upward from the cylinder head and extending in the direction of the crankshaft. The valve train area and the plurality of vertical fins are all integrally formed with the cylinder head, so that the cylinder head can be made thinner and lighter with high rigidity to enable the portable machine to become smaller, lighter, and more powerful.