Résumé
Most of the massive stars appear grouped in giant molecular clouds. Their strong wind activity generates large structures known as super bubbles and induces collective effects which could accelerate particles up to high energy and produce gamma-rays. The best objects to observe these effects are young massive star clusters in which no supernova explosion has occurred yet. Such star associations are typically still embedded in their parent molecular cloud, which can be traced traced out by the stellar light (HII region) emission due to ionization. Modelling this region such as a spherical. Considering this region as a spherical leaky-box surrounding a central cosmic ray source, a phenomenological model has been developed to estimate cosmic-rays and gammarays production for a set of selected clusters. In particular the expected high-energy gamma-ray emission has been finally estimated and compared to the present and future gamma-ray telescopes sensitivities.