Analysing a silicon semiconductor, the detector gets used in higher intensity region than the region in which the intensity is linear and the reliability of its intensity is asked, because the doped layer becomes shallow and the doping concentration becomes high in recent years. In order to compensate the intensity which has been reduced by the detector saturation, the following formula is used. The compensated intensity (n(0)) is given by n(0) = n/(1 - n tau), where n is the raw intensity and tau is the dead time. Generally, when compensating the intensity, it is considered that the dead time is constant. In this study, dependence of the dead time on the analysis condition (the rastering area and the beam diameter) is evaluated. (C) 2008 Elsevier B. V. All rights reserved.