An unit for surface profile reconstruction in SEM has been developed, based on directional detection of the secondary electron signal and its analog processing. It has been established that the sensitivity to particular kind of contrast and limitations due to shadowing errors depend on the range of emission angles of secondary electrons accepted by detectors. Thus, the unit is equipped with a detector head composed of two miniature scintillator detectors and electrodes for electrical control and optimization of the detection angles to obtain given kinds of information. The signals are processed according to revised formulas that enable one to obtain images with pure material and topographic contrast or profiles of surfaces sloped up to 70° (reckoned between the electron beam axis and the normal to the surface at given point).