Ernst Ruska was born inHeidelberg, Germany. He was educated at theTechnical University of Munich from 1925 to 1927 and then enteredTechnische Hochschule Berlin (nowTechnische Universität Berlin), where he posited thatmicroscopes usingelectrons, with wavelengths 1000 times shorter than those of light, could provide a more detailed picture of an object than a microscope utilizing light, in which magnification is limited by the size of the wavelengths. In 1931, he demonstrated that a magnetic coil could act as anelectron lens, and used several coils in a series to build the firstelectron microscope in 1933.
After completing his PhD in 1933, Ruska continued to work in the field of electron optics, first atFernseh AG inBerlin-Zehlendorf, and then from 1937 atSiemens-Reiniger-Werke AG. At Siemens, he was involved in developing the first commercially produced electron microscope in 1939. As well as developing the technology of electron microscopy while at Siemens, Ruska also worked at other scientific institutions, and encouraged Siemens to set up a laboratory for visiting researchers, which was initially headed by Ruska's brotherHelmut, a medical doctor who developed the use of the electron microscope for medical and biological applications.
After leaving Siemens in 1955, Ruska served as director of the Institute for Electron Microscopy of theFritz Haber Institute until 1974. Concurrently, he served at the institute and as professor atTechnische Universität Berlin from 1957 until his retirement in 1974.
