PURPOSE: To inhibit the formation of tar and to maintain instantant ignition and extinction property in an oil burner, by bearing an oxidizing catalyst such as platinum or palladium on a vaporizing wall in high temperature.

CONSTITUTION: The feed oil, being fed from a fuel feed tube 2, is atomized by an air flow which is injected from an air feed port 1, is instantly vaporized on a preheated vaporizing wall 6, and is mixed with the combustion air. The premixed gas, after being mixed further with the air during passing through a throttled port 7 and the distribution of velocity is uniformed by a straightening plate 8, is ignited by discharge by ignitors 16 and 17 to form stable flames 10 on a burner port plate 9. In case that oil of high boiling point such as deteriorated kerosene or impure kerosene is mixed with the fuel, formation of tar is inhibited by the oxidizing action of a catalyst 19, if the temperature of a vaporizing wall 6 is higher thab about 250°C. With such an arrangement, safe and comfortable burner with instant ignition and extinction can be obtained.