A hydrophilic membrane having a low adsorptivity for a protein is disposed,
as an interface, on a side to be contacted with a skin, and a drug such as
a physiologically active peptide is transdermally delivered by
iontophoresis. The membrane has an adsorptivity for a protein of not
greater than 10 .mu.g/cm.sup.2. The thickness of the membrane is about 10
to 200 .mu.m, and the porosity of the membrane is about 60 to 90%. Such
membrane includes a hydrophilized fluororesin membrane, a hydrophilized
polysulfone membrane and a hydrophilized cellulose derivative membrane.
