[en] The 27 km long ultra-high vacuum system of LEP has been successfully operated during the first year of running. In most of the 130 vacuum sectors, with lengths up to 474 m, an average pressure of about 5 10-10 Torr has been achieved in the presence of circulating beams. The performance and the experience with the operation of the pumping system of LEP, which uses a combination of non-evaporable getter strip (NEG) and lumped ion pumps is described. The reduction of the synchrotron radiation induced pressure rise with the accumulated beam dose has followed closely the behaviour expected from measurements on test vacuum chambers. After several months of operation the beam lifetime due to gas scattering has increased from several minutes, for the very first circulating beam, to many tens of hours for colliding beam runs. (author) 11 refs.; 5 figs