<p>It is intended to provide an iontophoresis apparatus for administering an ionized drug provided with a working electrode structure, which holds a drug solution containing the drug, and a non-working electrode structure, which holds an electrolyte and faces to the working electrode structure (200) via a space at least in using. In using, the gum is put into the space between the non-working electrode structure and the working electrode structure and thus the drug is administered via the gum. Use of this iontophoresis apparatus makes it possible to apply iontophoresis to the gum while stably passing an electrical current.</p>
