In recent years, X-ray synchrotron radiation became a powerful tool for studies of condensed matter, and in view of that a proposal for the construction of a European Synchrotron Radiation Facility (ESRF) was elaborated in some detail by the European Synchrotron Radiation Project. The heart of the proposed Facility is a 5 GeV electron storage ring with a 100–200 mA electron current and a characteristic wavelength of 0.9 Å from bending magnets. The storage ring, 776 m in circumference, is able to accommodate up to 30 wavelength shifters, multipole wigglers and undulators. It is characterized by a great flexibility and a small emittance (7×10 −9 rad m) leading to a very high brilliance (10 19 photons/(s mm 2 mrad 2) in a relative bandwidth of 0.1% in case of a 1 Å undulator). The overview, as seen from the users point of view, gives a brief account of the storage ring, emitted radiation, instrumentation and cost. More details can be found in ref. [1].