The Cluster of Excellence PRISMA addresses the basic questions about the nature of the fundamental building blocks of matter and their importance for the physics of the universe. PRISMA consists of renowned research groups that work primarily in the areas of astroparticle, high energy and hadron physics, nuclear chemistry as well as precision physics with ultra-cold neutrons and ion traps. Conducting various new key experiments to study the fundamental forces and limits of the Standard Model is one of the main initiatives of the Cluster. PRISMA is divided into four research fields and four structural measures. Research Field A - Fundamental Interactions is concerned with the indirect search for new physics. The most important structural measures are the construction of a superconducting energy-recovering accelerator (MESA) and the expansion of the existing TRIGA reactor to a user facility designed for the world's most powerful source of ultra-cold neutrons. Participation in international large-scale projects such as the ATLAS experiment, the IceCube Neutrino Telescope, and the XENON Project to search for dark matter is the foundation for Research Field B - The Origin of Mass, which deals with the search for the Higgs boson, WIMPs, and other particles in Standard Model extensions. Research Field C - The Structure of Matter is concerned with studying the complex internal structure of hadrons, which will be particularly promoted through the establishment of a research center on the analysis of hadron structure. The methods of theoretical physics are at the core of Research Field D. The planned Mainz Center for Theoretical Physics (MITP) is to assume the role of an international theoretical center in Germany for the long term. The PRISMA Detector Laboratory is another structural target for joint innovative detector construction and development of the entire Cluster.