To obtain an antiallergic food or antiallergic agent with no side effects, having antiallergic activity, and useful as a health food having beauty effects such as skin beauty and rough skin prevention, or in medicaments by including trihydroxyflavanone.

This antiallergic food or antiallergic agent with no side effects, having antiallergic activity, is obtained by formulating trihydroxyflavanone in, e.g. candy, drops, tablet confectionery, chewing gum, gelatin capsules, drink, or by pharmaceutical manufacturing through formulation of trihydroxyflavanone as an active ingredient in a vehicle or the like. By the way, the above trihydroxyflavanone can be abtained by the following procedure: the fruits, leaves, stems, roots, or the like, of thyme or perilla as a plant belonging to Labiatae are ground using a ball mill or the like, and then subjected to extraction with a low-boiling solvent such as ethanol, n-hexane, ether, acetone or water, the resulting extract liquid is evaporated under a vacuum by heating or the like to afford flavonoids, which, in turn, are separated and purified by column chromatography or the like.