  The physics motivations and the detector design of the long baseline OPERA
experiment are discussed; OPERA is a hybrid detector made of several types of
electronic subdetectors, 2 magnets and lead/nuclear emulsions ``brick'' walls.
It is located in the Gran Sasso underground lab, 732 km from CERN, on the CNGS
neutrino beam. A summary of the performances and of the physics plans are
presented.
