PURPOSE: To prevent the deviation of combustion exhaust gas locally and to prevent the deterioration of properties of combustion exhaust gas, by a method wherein a partition plate with a hole is situated above a burner, a sucking action is created at an end of each of the partition plate and a plate body by an air current from a fan.

CONSTITUTION: When fuel sucked up from a fuel tank 1 as a result of an ignition is burned, a fan 15, simultaneously, runs to blow downward an air current along an air tunnel 20, and the air current is mixed with combustion exhaust gas from a burner 12 and is blown as hot air through a supply opening 21. Combustion takes place in the vicinity of pores 12a part in a burner 12, and a gasification of fuel is continued by the heat of a flame produced in the pores 14a to continue combustion. The supply of a combustion air required by combustion is such that, when an air current passes through the air tunnel 20 from the fan 15, combustion exhaust gas is exhausted through a combustion cylinder 13 and a hole 17 in a partition 18 as shown by a dashed line arrow mark through the creation of a sucking action by the action of an ejector at the end of each of the partition plate 18 and a plate body 19, and this causes the combustion air to be sucked from below.