SESAM stands for "Sub- eV -sub- Ångstrøm -Microscope". The aim of the project is to develop a TEM/STEM which combines the advantages of both types of instruments. The SESAM project is based on three development stages, specifications of which are shown in Table 1. in the final stage an information limit below 1Å and an energy resolution of 0.2 eV is strived for.
Compared to previous energy-filtering microscopes SESAM I is equipped with a 2nd order corrected energy filter . Due to the high transmissivity  large scattering angles up to 150mrad at ΔE=20 eV are accepted by this filter which can be used in electron diffraction experiments. A diffraction pattern of amorphous SiBCN ceramic is shown in Fig.l together with a profile. Since the diffracted intensity can be integrated over 2π, high statistical accuracy is achieved even at a moderate exposure time (10s). in energy-filtered imaging large specimen areas are imaged isochromatically.