On one end face of a case, a heating unit, a burner and a firing portion are aligned in this order, and a tubular windshield is mounted on the end face of the case to surround substantially entirely the burner. The windshield has formed therein an opening on the side of the heating unit, through which a lighter flame emitted from the burner is directed to the heating unit to set it alight when the case is turned down so that the heating unit lies above the burner.