PURPOSE: To obtain a stabilized atomization characteristic to the change in the feeding rate of fuel oil, by fitting a porous material to the inside wall of a cylindrical rotator, having a bottom, to which injection ports are provided.

CONSTITUTION: Fuel dripping into a cylindrical rotator 13 passes through it, filling the pores of a porous material 19 by the capillary action of pores and the centrifugal force of the rotator, and is injected from one or a plural number of injection port(s) 20 (round hole(s), oblong hole(s), slit(s), etc.) provided on the side wall of the rotator to form atomized particles on it. By fitting the porous material to the inside of a cylindrical rotator having injection ports on its side wall, semi-transparent buffer resistance body is formed on the material if the fuel oil is fed getting out of position to some extent or its feeding rate is changed; ununiformity in quantity of generation of fine particles of fuel and the injecting direction of fuel particles do not occur the fuel is atomized in a wide range with stabilized atomization characteristic; and it is widely spread over the vaporizing surface of a vaporizing chamber; so that deviation of fuel load can be decreased.