PURPOSE: A skin treating agent, obtained by dispersing and suspending stone powder homogeneously in a polyelectrolytic solution, e.g. a water-absorbing resin solution, reactive with components in sweat to reduce the viscosity thereof, capable of removing horny substance on the skin surface and detecting an accurate potential.

CONSTITUTION: A skin treating agent, obtained by dispersing and suspending stone powder homogeneously in a polyelectrolytic solution reactive with components in sweat, e.g. electrolyte such NaCl or lactic acid, to reduce the viscosity thereof and containing the polyelectrolytic solution and the stone powder, and useful for treating the site of the skin for mounting an electrode. A water-soluble resin, e.g. ammonium polyacrylate or Carbopol, water-absorbing resin, e.g. polyacrylic acid based Aquakeep (manufactured by Seitetsu Kagaku Co., Ltd.) may be cited as the polyelectrolytic solution. The agent has a high viscosity when not in use and gives a low viscosity on reaction with the sweat in use and the skin is readily rubbed with simple post-treatment. The horny sybstance can be readily removed and an accurate potential such as electrocardiogram can be detected.