The enhanced interest to nanocrystalline (NC) materials is attributed to their unusual physical properties significantly different from those of usual coarse-grained counterparts. A large volume fraction of grain boundaries within NC metals and their special, non-equilibrium states play a crucial role in formation of specific properties, particularly in appearance of some peculiarities in electronic structure. So, these materials are intriguing because they hold promise for technological manipulations. NC metals are expected to be applied for development of new effective cathodes. The NC structure with average grain size about 100 nm was processed in specimens of tungsten by severe plastic deformation. The microstructure was studied by ion and transmission electron microscopy