The research subject of this Department is cosmic rays, especially in the energy range above 10¹⁸ eV. Particles with so high energies – several orders of magnitude higher than energies attained in terrestrial particle accelerators – arrive to the Earth from Space. The origin of these particles is not known and is one of the most important puzzles in present-day astrophysics. The Pierre Auger Project, in which we participate, is devoted to explanation of this puzzle. A wide international collaboration constructs the Pierre Auger Observatory. It is expected that the experimental data from the Pierre Auger Project will help us understand the most violent processes in the Universe