2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/154064A review of the main issues in the field of particle acceleration in Supernova Remnants is provided in the context of future X-ray observations with Simbol-X. After a summary of the nonthermal acceleration mechanisms at work, I briefly review the observations of supernova remnants in hard X-rays and in gamma rays. Open issues are discussed in this framework.6 pages, 3 figures, invited talk at 'Simbol-X: the hard X-ray universe in focus', Bologna (Italy), 14-16 May, 2007. To appear in Memorie della SAItAstrophysicstext