The research programme is devoted to measurements in the field of elementary particles, to reveal the ultimate building blocks of matter and the nature of interactions between them. The main topics studied are strong, weak and electromagnetic interactions, fundamental symmetries and heavy-quark physics. The research includes applications of experimental methods of high-energy physics to other fields demanding state-of-the-art technology. Experiments are carried out within large collaborative programmes at international centres for particle physics at CERN near Geneva (experiments ATLAS, CPLEAR and DELPHI), at DESY in Hamburg (HERA-B) and at KEK in Tsukuba (Belle). The research programme represents science at its very frontiers, in terms of its goals, the technology required as well as the human and financial resources used. It has been approved and is being attentively reviewed by Research Boards of international centres and the relevant bodies of the Funding Agencies involved. The experimental research calls for accelerators of highest obtainable energies or unique properties that enable broadening of our knowledge of Nature. High energies lead us into the Universe as it existed shortly after the Big Bang and thus contribute to the understanding of the creation of the world around us. Symmetries in Nature and their violation are among the most powerful tools of today's science. Violation of CP symmetry is one of the necessary conditions for prevalence of matter over anti-matter in the Universe and thus of our own existence. The experiments of the research programme have carried out precise measurements of CP violation in the neutral kaon system, and discovered CP violation in the system of B-mesons. The Standard model of strong and electroweak interactions, one of the most celebrated theories of our time, has been thoroughly scrutinized by experiments of this research programme. The experimental hint of a possible existence of a Higgs boson with a mass of 114 GeV represents a guideline to future experimental searches at the Large Hadron Collider. The success of experiments would be impossible without substantial research and development work, including several breakthroughs in the fields of detector technology, electronics and computing. Although the field is devoted to basic research into the nature of the Universe, the very existence of a joint endeavour of this magnitude constitutes an ideal breeding ground for new products and technologies. Developed primarily to make the experiments feasible, many of them find widespread application in other areas. The obvious showcase is undoubtedly the World Wide Web. Conceived at CERN as a communication exchange facility for the big collaborations at the LHC, it has in the past years developed into an indispensable tool in almost every field of human endeavour. A similar boost as WWW provided for information exchange is expected in general information technology, from the implementation of Grid-based technologies. Grid as the ultimate globalization of computing resources on the network is being pursued by the high-energy physics community as the only viable option for data analysis for experiments currently constructed at the Large Hadron Collider. European Grid infrastructure is being developed within the scope of EGEE, approved in August 2003 as the reference integrated project in the 6th framework programme of the EU.