This conference was attended by leading experts in the field of gamma-ray astronomy as well as students and postdocs from around the world. The symposium concerned the basic observational and theoretical topics and the objectives of the rapidly developing field of gamma-ray astronomy in the energy range above 10 GeV, with emphasis on the connections between physics at GeV and TeV energies by which the most violent processes in the universe manifest themselves. The topics ranged from particle acceleration in different astrophysical environments, the origin of cosmic rays, and the relativistic astrophysics of jets and winds from compact galactic objects and active galactic nuclei, to observational cosmology. They comprised almost all known and expected gamma-ray populations and their contributions to the non-thermal inventory of the Universe. The symposium was primarily concerned with the scientific aspects of the field and less with the development of instrumentation.