PURPOSE: To obtain the title ingredient improved in biocompatibility without impairing use feeling by coating the surface of crosslinked spherical polystyrene fine granules with hydroxyapatite.

CONSTITUTION: Styrene is singly polymerized, or a monomer mixture of styrene and ≤20wt.% of a monomer copolymerizable with styrene at the weight ratio (80-90):(10-20) is copolymerized, in the presence of a polyfunctional crosslinking agent (e.g. divinylbenzene), thus obtaining the objective crosslinked spherical polystyrene fine granules of 8-25μm in size accounting for ≥85vol.% of the total granules and coated with hydroxyapatite. The coating is carried out by adding to the monomer components in their charge followed by making a polymerization. The hydroxyapatite is a component of the teeth or bone in biological body and good in the affinity for the biological body, thus being expected for the suppressive effect for skin inflammation which might be caused in the repeated use of cosmetics.