CUPID (CUORE Upgrade with Particle Identification) is the upgrade of the CUORE experiment. CUPID is a leading next generation of rare event experiments. Designed to search and investigate the 100Mo double beta decay aims at reducing CUORE radioactive background by 2 order of magnitudes. It will enable the exploration of the inverted hierarchy of the neutrino masses and to access rare processes with probabilities as low as 10^-27 y^-1.