PURPOSE: To reduce the producing of hydrocarbon compound and odor at the cut-off of burning of the titled device by a method wherein a suction means of a igniting heater is still operated during a certain period after the cut-off of burning.

CONSTITUTION: Just after the cut-off of burning, large amount of unburned gas still remains in a burning chamber 6. When a wick 3 is lowered by the burning cut-off operation, an igniting heater 8 and a fan 17 are simultaneously electrified and kept at electrified condition during designated period. The condition in said burning chamber 6 after the cut-off of burning is kept under negative pressure by the ejector effect produced by the air flow from said fan 17. Accordingly, the air is introduced into said burning chamber 6 from air openings 13 of an outer fine tray part 12 and air openings 14a of a burner 14. Thereby, whole space area of said ring-shaped burning chamber 6 is rapidly maintained at combustible condition. A flame ignited by said igniting heater 8 is instantly spread over whole space area inside of said burning chamber 6, the remaining unburned gas is burnt out. Thus, the producing of hydrocarbon compound and odor can be reduced.