The methodology and an automated program, which allow using the accelerated measurements of the test structures composed of plates to identify the dielectric defects and to assess its operating time to failure, have been developed. The results of calculation of the dielectric defects with the account of the effect of the isolation and diffusion boundary have been presented. It has been shown that this technique can be used for monitoring the parameters of the manufacturing processes of the gate dielectric and forecasting the long-term reliability of MOS-transistors.