© 2014 Elsevier B.V. The detoxification mechanism of asbestos materials was investigated through simulations and experiments. The permittivities of pure CaO and Mg3Si4O12, as quasi-asbestos materials, were measured using the cavity perturbation method. The real and imaginary parts of the relative permittivity (e{open}r' and e{open}r″) of CaO are functions of temperature, and numerical simulations revealed the thermal distributions in an electromagnetic field with respect to both asbestos shape and material configuration based on permittivity. Optical microscopic observation revealed that the thickness of chrysotile fibers decreased as a result of CaO heating. The heating mechanism of asbestos materials has been determined using CaO phase, and the detoxification mechanism of asbestos materials was discussed based on the heating mechanism.