An array of feed horns and receivers mounted at the focus of a radio telescope which form a number of independent beams on the sky. Multi-beam receivers considerably reduce the time taken to complete a radio source survey, the actual time saving depending on the numbers of beams. A 13-beam receiver was installed in 1997 at Parkes Observatory, Australia, and receivers with over 100 beams operating at millimetre and submillimetre wavelengths are now in use.