PROBLEM TO BE SOLVED: To provide a diketone action inhibitor capable of effectively suppressing the action of a diketone caused by dermal components, and to provide a body odor inhibitor capable of effectively suppressing the body odor, especially acid odor in the armpit part and oil odor in the head part.SOLUTION: There are provided a diketone action inhibitor for suppressing the action of a diketone represented by general formula (I): R-(CO)-(CO)-R(wherein, Rand Rare each independently 1-4C alkyl), resulting from dermal components, and containing at least one kind of extracts selected from the group consisting of extracts of licorice, Artemisia princeps, cinnamon, cherry, Aesculus hippocastanum and tormentilla and a body odor inhibitor containing the diketone action inhibitor.
