An iontophoresis device comprising (A) a working electrode assembly having a working electrode, a medicine-containing portion and an ion-exchange membrane, (B) a counter electrode assembly having an electrode which opposes the working electrode, and (C) a power source unit electrically connected to the working electrode assembly and to the counter electrode assembly, enabling an ionic medicine contained in the medicine containing portion to be permeated into a living body by the electrophoresis through the ion-exchange membrane, wherein the ion-exchange membrane has a structure in which voids of a porous film are filled with an ion-exchange resin. The iontophoresis device using the above ion-exchange membrane makes it possible to administer the medicine in amounts larger than those accomplished by using the conventional devices.