Erwin Wilhelm Müller (13.06.1911 - 17.05.1977) was a German physicist. He was born in Berlin. He graduated from the Higher Technical School in Berlin (1935). In 1935-37 he worked at the Siemens laboratories, in 1937—45 at the Stabilovolt Company, in 1945 —47 he was professor at the Technological Institute in Altenburg, and in 1947 —52 he worked at the M. Planck Institute in Berlin. From 1952 he was professor at the University of Pennsylvania. His research was in electron and ion microscopy and metallurgy. He invented the field-emission microscope in 1936 and showed (1943) the limit on the resolving power of the field-emission microscope. In 1950 he obtained the first detailed image of a molecule with the help of a field-emission microscope. In 1951 he invented the field-ion microscope, obtaining an image of the surface of an emitter with the help of positive hydrogen ions and, with the ion projector, achieving atomic resolution. In 1956 he discovered the phenomenon of evaporation under the action of a field. He achieved direct observation of the crystal lattice and its defects at the atomic level (1958) and the possibility of counting vacancy concentrations directly, and obtained images of structural defects, slip bands and twins (1959). He was the first to observe (1967) domain structures in order — disorder phase transformations, and obtained images of biological molecules. He created (1968) the ion projector with an atom probe, capable of identifying a selected single atom on a metal surface.