  The aim of the OPERA experiment is to search for the appearance of the tau
neutrino in the quasi pure muon neutrino beam produced at CERN (CNGS). The
detector, installed in the Gran Sasso underground laboratory 730 km away from
CERN, consists of a lead/emulsion target complemented with electronic
detectors. After a short pilot run in 2007, a first physics run took place from
June to November 2008. The second physics run started in June 2009. At present
a total (2008+2009) of 4.2 10$^{19}$ protons on target were delivered by the
CNGS, producing more than 25,000 events in time coincidence in the OPERA
detector. Among them \~4000 events occured in the target of the detector. In
this paper the detector and the analysis strategy are described and the status
of the analysis of the 2008 and 2009 runs is discussed.
