DESY: its past, present and future

The traditional programme undertaken at Deutsches Elektronen-Synchrotron (DESY) is investigating the structure of matter, its constituents and the forces which bind them together by using electrons as probes. The synchrotron and electron storage ring system (DORIS) and experiments which have been completed or are now underway on these machines, are described. It is now proposed to extend the present facilities at DESY by adding a larger e+e- storage ring, PETRA, with a maximum beam energy of 19 GeV. In a second phase this energy could be increased to about 23 GeV by simply adding more RF power and to more than 30 GeV if superconducting RF cavities become available. With this facility the most favourable and cheapest opportunity will be offered to European and other elementary particle physicists to continue research in the exciting field of e+e- annihilation. A brief description of the structure of DESY is given. (U.K.)