Photoemission electron microscopy (PEEM) combines in a unique way light-optical probing with electron-optical imaging. The fundamental process underlying this type of microscopy is the photoelectric effect, which describes the emission of electrons from a solid surface, when ultraviolet light is absorbed. PEEM typically utilizes light from synchrotrons, lasers and ultraviolet lamps. The technique provides for specific and gentle probing of surface properties, and it allows the recording of fast dynamic processes with time resolution down to the femtosecond regime. Over the last years we designed and built a new aberration-corrected PEEM which recently reached 5 nm resolution. We are now using this instrument for the visualization of surface plasmons in nanostructures, multi-photon excitation experiments, and for the imaging of biological structures. The basic ideas underlying the instrument design and first experiments will be discussed.