PURPOSE: To obtain a wick which is almost free from an influence of tar, by mainly composing the vaporizing part of a wick with heat-resistant fiber of below 2 microns in size.

CONSTITUTION: The vaporizing part 3 of a wick is composed of fiber below about 2 microns in diameter. Kerosene is vaporized from the surface of a fuel vaporizing part 3. In case that kerosene, mixed with an oil of different quality, or degenerative kerosene is used, tar is accumulated on the surface of a vaporizing part 3, but most of tar is vaporized by thermal decomposition, as soon as it is accumulated on the surface. Because the vaporizing part 3 is made of porous material, unfavorable influence such that remarkable lowering of combustibility will scarcely occur in a combustor, even if some quantity of tar will remain on the surface. By composing the fuel vaporizing part with such a fiber, unfavorable influence by tar to a wick can largely be decreased.