I will present the basics of the Survey for High-z Absorption Red and Dead Sources (SHARDS). SHARDS is an ESO/GTC Large Programme awarded with 180 hours of GTC/OSIRIS time. The survey aims at studying in detail the stellar populations of the massive galaxies which were already in place at high-z (z=1-3). A detailed spectro-photometric analysis of these sources is essential to understand the downsizing scenario of galaxy formation and constrain the current cosmological models of galaxy evolution, which are challenged by the existence of such a population of massive galaxies evolving passively at early stages of the Universe history.
SHARDS is already the deepest medium-band survey in the sky and have multiple ap
plications in the study of galaxy evolution at z=0-4.