PURPOSE: To obtain the granulated powder having high fluidity by granulating raw fine powder into a spherical body having 30W100μm particle diameter with a rotary spraying machine.

CONSTITUTION: When the spherical body having 30W100μm particle diameter is granulated by using a rotary spraying machine, the temp. of the waste air is kept at 70W120°C, and the number of revolution of the rotating disk is regulated to 6,000W19,000r.p.m., preferably to 8,000W17,000r.p.m. A slurry for granulation is supplied from the upper part to the central part of the rotating disk. The slurry for granulation consists of raw fine powder having 0.4W6μm particle diameter, a binder such as polyvinyl alcohol, acrylic base, or paraffin, and a solvent (trichloroethylene, etc.). The viscosity of the slurry is preferably regulated within the range of 100W600cp.