The Swedish 1-m Solar Telescope (SST) on the island of La Palma, Spain, had first light with a stopped down 60 cm aperture on March 2, 2002. On May 21, the telescope was opened to full aperture and the adaptive optics system was switched on for the first time. Already on the second day of operation it delivered diffraction-limited images, i.e. it reached the theoretical resolution limit for a telescope of this size. This means the SST has very small optical aberrations after compensation by the adaptive optics system, designed to counteract blurring caused by the atmosphere. This enables solar astronomers to see and photograph solar details of smaller size than previously possible.The SST will address current and important questions concerning solar magnetic fields and the dynamics of the upper solar atmosphere and will also be used to improve our understanding of the formation of stellar spectraTurret with side-view of lens The front lens of the SST has a diameter of just under 1 meter, making it the largest optical solar telescope in Europe and the second in the world, after the McMath-Pierce telescope in Arizona, USA. Located on the best known site for solar telescopes in the world, it can see details as small as 70 km on the solar surface. This requires the use of a so-called adaptive mirror that corrects for the blurring caused by the Earth's atmosphere 1000 times per second. The SST is the first solar telescope that is designed for use with such a mirror.The SST is operated by the Institute for Solar Physics of the Royal Swedish Academy of Sciences but located within the Observatorio del Roque de los Muchachos of the Instituto de Astrofísica de Canarias on the island of La Palma, Spain. The SST replaces a previous 50 cm telescope that has been a world leading solar research instrument for over ten years.