Installation of the world’s largest silicon tracking detector was successfully completed at CERN on December 18, 2007. With a total surface area of 205 square metres, about the same as a singles tennis court, the CMS Silicon Strip Tracking Detector is by far the largest semiconductor silicon detector ever constructed. Its silicon sensors are patterned to provide a total of 10 million individual sensing strips, each of which is read out by one of 80,000 custom designed microelectronics chips.