An iontophoresis device, which can ensure the long-term stability of drugs and which can be easily assembled when used, is provided. A donor electrode-printed portion (6) is placed on one side of a backing layer (4), and a reference electrode-printed portion (7) is placed on the other side. Both printed parts are connected to a current generating part (Ia) through a connector (Id). A drug support film (14) is joined to a drug-dissolving portion (11), and a cup-like shaped protective cover (12), which covers the drug support film (14), is removed before the device is used. The exposed drug support film (14) is attached to the skin of a user, and the device is driven by turning on a power supply of the current-generating portion (Ia).