An object to be achieved by the present invention is to provide a microneedle array which is able to supply effectively retinoic acid to the skin and effective in treating pimples, stains or wrinkles. The retinoic acid microneedle array comprises: a microneedle array having a microneedle substrate 5 and microneedles 1 disposed on the microneedle substrate 5； and a drug retained on the microneedles 1 and containing a water-swelling polymer and retinoic acid.
