The CMS tracker and its performance

The Compact Muon Solenoid CMS is one of the two general purpose detectors planned at the Large Hadron Collider at CERN. The main physics goals of CMS include the search for the Higgs boson, for signs beyond the Standard Model and an accurate measurement of CP violation in the b-system. These goals and the hostile radiation environment at the LHC represent a challenge for the tracker which will utilise a system of silicon pixel detectors, silicon strip detectors and microstrip gas chambers. The design of the tracker and its performance in selected aspects of b-physics are presented in this paper.