Research and development projects on materials for applications exposed to high temperatures and radiation include comprehensive mechanical and metallographic examinations as well as analysis methods based on electron microscopy investigations using SEM (scanning electron microscope) and TEM (transmission electron microscope). In addition to 2D EDS and EBSD analyses in the μm range, the imaging 3D analysis method has become more and more important in the past few years. Particularly, the combination of SEM images with simultaneously obtained EDS and EBSD data during 3D analyses is a test method which complements previous material testing and produces clear results since much larger data sets are used in order to determine the composition of a material and the phases present in its microstructure. Since 2014, our institute has been working with a workstation (FIB/SEM) from the company Zeiss, a crossbeam AURIGA 40 with 3D analysis. This paper will present unparalleled results of the investigations carried out on the structural and high-temperature material 12Cr0.36Ta steel, nanocrystalline tungsten and intermetallic NiAl-Cr alloys using the above-mentioned 3D technique.