Disclosed are: a skin whitening agent comprising, as an active ingredient, acomplex of carbonic acid and/or bicarbonic acid, a metal and an LF, a decompositionproduct 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 cosmeticcomprising the skin whitening agent. The skin whitening agent can be ingestedsafely on a daily basis, and exhibits an excellent skin whitening effect.