ZEUS is a collaboration of about 450 physicists which has been running a large particle detector at the electron-proton collider HERA at the DESY laboratory in Hamburg. The ZEUS detector is a sophisticated tool for studying the particle reactions provided by the high-energetic beams of the HERA accelerator. Thus the participating scientists are pushing forward our knowledge of the fundamental particles and forces of nature, gaining unsurpassed insight into the exciting laws of the microcosm.