Abstract
The broadband dielectric spectroscopy of epidermis at inner forehand using the coaxial probe electrodes with various measurement depth was performed to evaluate the distribution of free water in depth direction and the water relaxation dynamics. The skin at inner forehand was moistened for 30min and was exposed under the environment of 25°C - R.H.20%, followed by the dielectric spectroscopy at few min intervals. It was found that at the deep part of the skin a dielectric relaxation was observed between 100nsec and 1µsec（～10psec for free water）. The distribution of free water volume ratio linearly increases from the surface of the skin to 200µm in depth. At the depth 200 ～600µm, the inclination of the water distribution becomes relatively flat where a small peak exists just after the humidification. The water distribution below 600µm is almost flat at any time.
