Gathering around 740 people, the “Laboratoire de Physique des 2 Infinis Irène Joliot-Curie” (Laboratory of the Physics of the two infinities Irène Joliot-Curie) or IJCLab is a joint research unit of CNRS, Université Paris-Saclay and Université de Paris, located on the Orsay campus. The identify of IJCLab is centred on the “physique of the two infinites” and their applications, with a wealth of subjects related to these domains of physics. This is featured by the presence of strong scientific departments in well-established disciplines, of scientific departments related to emerging fields and of interface activities. The scientific activities of IJCLab are organised around 7 scientific departments: Astroparticles, Astrophysics and Cosmology; Accelerator Physics, High-Energy Physics; Nuclear Physics, Theoretical Physics, Energy and Environment, Interface Life Sciences / Physics. They rely on an Engineering department organised following four technical departments in electronics, IT and computing, instrumentation and mechanical engineering, with a unique potential for designing, developing and exploiting the instruments required to take the scientific challenges of the coming decades. The presence of a vast set of research infrastructures and technological platforms is also an essential feature of IJCLab. This laboratory has the ability, the vocation and the ambition to make a global impact on a large range of scientific and technical topics by leading large-scale projects at the national and international levels. It also spurs and supports projects on a smaller scales and shorter cycles which can arise depending on recent scientific events and/or technical breakthroughs. Finally, this laboratory is situated at the heart of the Orsay-Saclay scientific cluster recognised at the global level. This puts IJCLab in an exceptionally favourable environment for teaching, training, transfer of knowledge and popular science.