A system and a method for fast characterization of sample's material composition, which is especially beneficial for semiconductor fabrication. The material composition is characterized by analyzing secondary electrons emission from the sample. According to one feature, electron detector is used to collect secondary electrons emanating from the sample. The detector is controlled to collect a specific narrow band of secondary electrons, and the band is controlled to allow for collection of SE at different energies. Two modes are disclosed: spot mode and secondary electron spectroscopy material imaging (SESMI). In the spot mode, a spectrum of SE is obtained from a single spot on the sample, and its characteristics are investigated to obtain information of the material composition of the spot. In the SESMI mode, an SEM image of an area on the sample is obtained. The SE spectrum at each pixel is investigated and correlated to a particular spectrum group. The image is then coded according to the SE spectrum grouping. The coding is preferably a color coding.