PURPOSE: To enable regulation of a combustion amount through simple consitution and to obtain a given distance of a wick elevating stroke through a short control stroke, by a method wherein an auxiliary lever is pivotally secured to the actuating part side of a main lever, and a wick elevating lever is engaged with the auxiliary lever.

CONSTITUTION: With a wick elevating knob 30 depressed, an edge 28c of a control body 28 loweres the control part side of a main lever 17. This causes raising of the actuating part side, and as a result, a shaft hole 24 in the auxiliary lever 22 is raised. A lever 8 is turned through a cam shaft 9 inserted in the shaft hole 24, a wick 4 is raised to a given position. In which case, since the main lever 17 forms a lever acting centering around a pivotally-securing part 18, a distance from the pivotally-securing part 18 to a large hole 19, positioned opposite to the cam shaft 9 for elevating the wick, is set to a size longer than a distance from the pivotally-securing part 18 to a control part, and this provides a long wick elevating stroke even if the depressing stroke of the wick elevating knob 30 is specified. Namely, a given size of a wick elevating stroke can be obtained through a short depressing stroke.