  The Pierre Auger Observatory aims to determine the nature and origin of the
ultra-high energy cosmic rays (UHECR). The Auger hybrid detector combines
fluorescence observations of extended air showers, initiated in the atmosphere
by these most energetic particles, with measures of the shower front at the
ground level by its large array of Cherenkov water tanks. This allows to
improve considerably the precision on reconstructed primary cosmic ray
parameters, and to make important cross-calibrations between two techniques at
these energies, unreachable with accelerator experiments. The Southern Auger
site in Argentina is close to completion. The first measure of the primary
cosmic rays energy spectrum, the anisotropy search results, and the limit on
the photon fraction in the UHECR are discussed.
