Aberration corrected electron microscopy has revealed various aspects of materials and their functions, i.e., interfacial, ionic, chemical, photonic, plasmonic, magnetic and electronic aspects. A 50 pm resolution microscopy, particularly, enabled us to observe lithium ions in LiMn₂O₄, a material used as lithium ion battery electrodes. The 50 pm electron probe scanning over the surface is sensitive enough to detect a single adatom/vacancy similarly to STM. The 50 pm microscopy, in transmission mode of observation, is useful for study of catalysis, as demonstrated for Au/TiO₂ in O₂ and/or CO environment. Aberration corrected in-situ electron microscopy provides atomic, ionic, and electronic properties, in relation to structures at “nano in macro”.