The temperature and frequency dependencies of the dielectric parameters for the human fingernail are used to analyse keratin degradation in high temperatures. Measurements were performed over the frequency range of 100 Hz to 100 kHz and at temperatures from 22 to 260 degrees C. The nail samples contained 11% water by mass at room temperature at a relative humidity of 70%. The results were discussed in terms of the distribution of relaxation frequencies and the activation energy for the conduction and polarization mechanisms in the keratin-water system. The information on the dielectric behavior of the keratin degradation might become handy in course of future research on biomaterials obtained from nail keratin. (C) 2010 Elsevier B.V. All rights reserved.