Institut fuer Experimentalphysik, Universitaet Hamburg. Annual report 2004-2005

In this report the acitivities of the named institute are described. These concern th H1- and the ZEUS-experiment at HERA, the CMS-experiment at the CERN-LHC, physics and experiments at the International Linear Collider, neutrino physics, astro-particle physics with H.E.S.S., detector development, accelerator physics, the nucleon-nucleon interaction, experiments with synchrotron radiation, short-time physics with X-ray pulses, X-ray optics for inelastic scattering, environmental physics, theoretical nuclear physics, as well as the application of natural sciences to international security. (HSI)