In this paper a set of simple methods is presented, to determine the main parameters of the silicon on insulator technology, using a thin film SOI-MOS capacitor. Methods to obtain the effective substrate doping concentration, substrate interface charge density and the buried oxide thickness using the two terminal Sol capacitor are presented. The front gate oxide thickness, the silicon film thickness, the silicon doping concentration and front and back interface charge density are obtained using a three terminal SOI-MOS capacitor. Bidimensional numerical simulations of SOI structure are performed for analyzing the high frequency capacitance vs. voltage curves and to test the proposed methods. These methods were applied experimentally and coherent results were found. (C) 2004 Elsevier Ltd. All rights reserved.