Since the invention of the electron microscope in 1931, its spatial resolving power remained trapped well below the theoretical limit for more than half a century: aberrations in the electron lenses — particularly spherical aberration — blurred the image in ways that no amount of worldwide effort, however intense, managed to resolve. Harald Rose, a German physicist, develops a novel optical concept to correct the spherical aberration of the objective lens of an electron microscope, based on a system of hexapole elements. Working together since 1990, Maximilian Haider builds, based on Rose's theoretical principle, the first functional prototype of an aberration-corrected transmission electron microscope, demonstrated in 1998 on a commercial 200 kV instrument equipped with a field-emission source: the instrument's resolution limit improves from 0.24 nm to better than 0.14 nm. Knut Urban develops this prototype into a real working platform for atomic-scale materials physics, and also builds the theoretical and methodological foundations for extending and interpreting microscopy at subatomic dimensions. The combined result allows, for the first time in history, individual atoms to be located with picometer precision — one hundredth the size of a hydrogen atom — and correlates atomic-scale structure with the macroscopic physical properties of materials. Within less than five years of its commercialization, more than 200 aberration-corrected electron microscopy instruments are acquired by university and industrial laboratories worldwide, ending decades of stagnation in this key scientific-instrumentation technology, with applications ranging from the study of graphene to chip miniaturization and molecular biology.