Virgo an interferometer for gravitational wave detection

Gravitational waves propagating from rapidly accelerating star masses can b e detected by means of interferometric techniques. The Virgo detector is a Michelson interferometer, with two 3 km long Fabry-Perot cavities, that is going to be built in the countryside of Pisa (Italy). Principles of interfe rometric gravitational wave detection, and the main noise sources in the Vi rgo apparatus are treated. The Virgo optical scheme and its main components are also described. Finally, an overview on the status of works at the Vir go site is presented.