A catheter-type iontophoresis device is adapted to cause a drug solution to permeate into a cancer site or the like of a digestive organ on a pinpoint basis by iontophoresis.The catheter-type iontophoresis device includes a working electrode assembly and a non-working electrode assembly for administering a drug by iontophoresis. A DC electric power source is connected to the working electrode assembly and the non-working electrode assembly with opposite polarities, and a rod-like member supports the working electrode assembly and the non-working electrode assembly at its tip. The rod-like member is detachably supported at a tip of a flexible cable supported by an endoscopic device.