The present invention provides an antiallergic agent comprising, as an active ingredient, at least one of a tomato extract, tomato pericarp, naringenin chalcone or its derivatives, tricaffeoylquinic acid or its derivatives and dicaffeoylsuccinylquinic acid or its derivatives; a histamine-release inhibitor or a leukotriene-release inhibitor; and a medicament, food, drink or cosmetic comprising the antiallergic agent, the histamine-release inhibitor or the leukotriene-release inhibitor mentioned above; and a method for producing an antiallergic agent comprising extracting raw material tomato with a solvent.