<p>Provided is an iontophoresis apparatus. In the apparatus, a doping layer is provided on an electrode in a working electrode structure or non-working electrode structure of the apparatus. The doping layer comprises a substance which can cause an electrochemical reaction by doping or dedoping of an ion (e.g., an ion of a conductive polymer). The apparatus can prevent or at least reduce the generation of a gas or undesirable ion which may be caused by the electrode reaction in an electrode structure or the denaturation of a medicinal substance which may be caused by any chemical reaction during energization of the apparatus.</p>
