SummaryIn Scanning Transmission Electron Microscopy (STEM) details at the top of thick specimens can be imaged with a better resolution than those at the bottom, because the scanning electron probe is broadened by multiple scattering. For quantitative measurement we used a test specimen consisting of a substrate film with an island‐structured indium film and coated with polystyrene spheres of different diameters up to 1.1 μm. The fine detail contained in the indium film was observed and the beam broadening was that caused by the polystyrene spheres. This specimen was imaged with the spheres both above and below the layer, in a JEOL 100B electron microscope with a scanning device. Electron energies from 20 to 100 keV were used. Images with the sphere below show a higher resolution than those with the sphere above and also those of conventional electron microscopical images at 100 kV and 200 kV. The broadening of the edges on the photographic film was recorded with a microdensitometer. The results can be compared with theoretical calculations by a Monte Carlo method. There is a good agreement with the experiments if one uses an effective aperture obtained by transmission experimen