ALEPH: une expérience de physique des particules

One of the physics group at the Laboratoire de Physique Nucleaire de Hautes Energies de l'Ecole Polytechnique has been taking part, for ten years, in one of the large electron positron collision experiment: ALEPH. The purpose of this experiment is to install our actual knowledge of the fundamental constituents of matter on well checked grounds and to open new perspectives. The theoretical frame of the experiment, the Standard Model, is described briefly as well as the experimental techniques and the main results. The structure of the collaborations in charge of such projects is described.