Disclosed is a skin whitening agent comprising, as an active ingredient, a complex of carbonic acid and/or bicarbonic acid, a metal and an LF, a decomposition product of the complex, or a complex of carbonic acid and/or bicarbonic acid, a metal and a decomposition product of an LF; and a food, beverage, feed or cosmetic comprising the skin whitening agent. The skin whitening agent can be ingested safely on a daily basis, and exhibits a skin whitening effect.