An annual meeting of scientific culture for nearly 30 years, the Science fair invites young and old to observe, experiment, question, discuss to understand the impact of science on their daily lives. It gives keys to understanding, in a fun way. In short, it arouses curiosity! Organized by the Ministry of Higher Education, Research and Innovation, the Science fair is made up of thousands of events for discovering science in a different way. Each year since its creation, I-SITE has participated in the organization of several events organized by the CNRS and the University of Lille in particular.