PURPOSE: To prevent the flocculation and the conglutination of the titled catalyst and to increase the catalyst activity by subjecting one or more kinds of compds. of Cu, V, Cr, Mo, W, Fe, Co and Ni to the sulfurizing treatment in the presence of the fine powder having ≤500mμ average particle size.

CONSTITUTION: A fine powder catalyst for treating heavy hydrocarbon is obtained by suspending the ultrafine powder having ≤500mμ average particle size in a solvent and thereafter adding one or more kinds of compds. of Cu, V, Cr, Mo, W, Fe, Co and Ni thereto and performing the sulfurizing treatment. The above-mentioned ultrafine powder is obtained by regulating the coarse powder of an inorganic substance and a carbonaceous substance to ≤500mμ preferably ≤100mμ average particle size with a build-up process. The sulfurizing treatment is performed by such a method that for example, the sulfides of the above-mentioned transition metals are directly separated with a precipitating method and deposited on the ultrafine powder or the transition metal compds. are deposited on the ultrafine powder with an impregnating method and thereafter subjected to the sulfurizing treatment.