[en] This work reports on the observations of γ-rays from the shell-type supernova remnant RXJ0852.0-4622 carried out with the High Energy Stereoscopic System in February 2004. H.E.S.S., a system of four imaging Cherenkov telescopes, is dedicated to the observation of γ-rays of energies between 100 GeV and several tens of TeV. Emission of -rays from RXJ0852.0-4622 was detected with a significance of 12σ within a live time of 3.2 h. The morphology of the emission region is clearly extended and correlated with the morphology of the X-ray emission. A differential energy spectrum of the photon flux between 0.5 and 10TeV was reconstructed. It is found to follow a power law dN/dE ∝E^-Γ with a spectral index of Γ=2.1 ±0.1_stat ±0.2_syst. The integral photon flux above 1 TeV from the entire remnant is (1.9 ±0.3_stat ±0.4_syst) x 10^-11 cm^-2s^-1 which is at the level of the Crab flux at these energies, establishing RXJ0852.0-4622 as one of the brightest γ-ray sources in the sky. RXJ0852.0-4622 is the second supernova remnant of which an extended γ-ray morphology could be proved. The observed energy flux in γ-rays between 0.5 and 10 TeV is calculated to be (9 ±1_stat ±2_syst) x 10^-11 erg cm^-2s^-1. Based on the energy flux in X-rays the expected energy flux due to inverse Compton scattering of relativistic electrons on the cosmic microwave background is estimated. It is found to be several orders of magnitude lower than the observed flux, suggesting that another radiation component significantly contributes to the γ-ray emission of RXJ0852.0-4622. In strong interactions of relativistic protons with the ambient interstellar material neutral pions are produced. The decay of these pions produce γ-rays. The distance to RXJ0852.0-4622 and the density of the ambient interstellar material are open parameters in the interpretation. It is shown for a wide range of these parameters that the transfer of several percent of the kinetic energy of the supernova remnant (∝10⁵¹ erg) to the acceleration of protons could explain the observed energy flux in γ-rays. Thus, it is likely that RXJ0852.0-4622 contributes to the acceleration of galactic cosmic rays. (orig.)