  We report a measurement of the flux of cosmic rays with unprecedented
precision and statistics using the Pierre Auger Observatory. Based on
fluorescence observations in coincidence with at least one surface detector we
derive a spectrum for energies above 10^18 eV. We also update the previously
published energy spectrum obtained with the surface detector array. The two
spectra are combined addressing the systematic uncertainties and, in
particular, the influence of the energy resolution on the spectral shape. The
spectrum can be described by a broken power law E^-gamma with index gamma=3.3
below the ankle which is measured at log10(E/eV) = 18.6. Above the ankle the
spectrum is described by a power law with index 2.6 followed by a flux
suppression, above about log10(E/eV) = 19.5, detected with high statistical
significance.
