PURPOSE: To reduce the generation of CO at the time of ignition by heating the fuel on the grill as well as an air chamber around the burner shell with an electric heater so as to quickly heat the fuel to a high temperature.

CONSTITUTION: The fuel 15 is fed on top of a grill 2, and an electric heater 3 is activated with a fan 11 stopped. The heat from the electric heater 3 preheats the fuel 15 on the grill by convection. As part of the hot generated by the electric heater 3 moves upward in an air chamber 9 through a connecting area 14 at the time of the preheating, to heat a burner shell 1 from outside, the heating of the fuel 15 is expedited. By feeding air to the fuel 15 with the fan after the fuel 15 reaches a predetermined temperature, the burning of the fuel 15 is started. Since the whole fuel 15 is heated to a high temperature, the CO generated in the lower part becomes easier to burn by reacting with the excess air in the upper part of the fuel layer, reducing the CO generation at the time of the ignition. Part of the air after the ignition flowing through the air chamber 9 and an air vent 16 helps the unburnt gas to be completely burnt above the fuel.