This "hands-on" material on elementary particle physics was collected on behalf of the European Particle Physics Outreach Group (EPPOG) for the yearly International Particle Physics Masterclasses. Comprising much more than just the masterclass exercises, it is well suited for general reading and learning about how the universe is built up from the basic constituents of matter and the forces between them.

Please look at Authors, to find the original Web Sites, their authors and the copyright information. The translations of the material into 15 languages was performed and organized by the Members of EPPOG.

Please contact the Coordinators of the "Hands on Particle Physics" Masterclasses for any further questions about the event and this material collection.