The structure of wood is complex with many components. As new cellulose-based materials and devices are to be developed and optimized it is crucial to understand the material microstructure of wood and also the properties of its individual microstructural constituents. Electron microscopy offers a unique capability for site specific imaging, diffraction and spectroscopy with high spatial resolution. For transmission electron microscopes (TEMs) the resolution can be better than 1 Ångström, i.e. we can resolve details smaller than the diameter of an atom. The limitation for the studies of plant cells and cellulose is the low contrast between different features in the structures, the sensitivity of the materials to the electron beam and the presence of water in pristine structures. The Eva Olsson group has a research profile working on direct correlation between local structure and properties. Interfaces are of particular interest due to their significant influence on the properties and microstructural evolution. The main research tool is electron microscopy and in situ techniques. We have established extensive knowledge about imaging, diffraction and spectroscopy of polymer thin films also including the specimen preparation. In addition, we have developed methods for in situ studies of the interaction of water and soft matter in the environmental scanning electron microscope.