Abstract: A Fischer-Tropsch reaction is conducted using a synthesis gas (mixture of carbon monoxide and hydrogen) as a raw material to synthesize hydrocarbons containing a large amount of olefin. These hydrocarbons are separated into a light fraction and a heavy fraction by means of a heat exchanger and an oxo process is conducted with respect to the olefin contained in the light fraction with a cobalt catalyst. As a result, an oxygenated fuel containing alcohol, aldehyde, etc. is manufactured. The oxygenated fuel made by such a manufacturing method is excellent in lubricity and oxidation stability, has a high cetane number, and is also capable of suppressing generation of soot when the oxygenated fuel is combusted.