The Laboratory for Emerging Nanometrology (LENA) at the TU Braunschweig has a Focused Ion Beam Microscope (FIB), an electron beam microscope, to which a FIB column has been attached on the side. Thus two beams point to the same spot: the focused ion beam of gallium ions processes a sample and the imaging electron beam provides images of it. The FIB can control the quality of nanostructures, produce TEM lamellas or prototypes and much more. The Technical University of Braunschweig explains its functionality in this article (in German).