  SHARDS (Survey for High-z Absorption Red & Dead Sources) is an unbiased
ultra-deep spectro-photometric survey with GTC@OSIRIS aimed at selecting and
studying massive passively evolving galaxies at z=1.0-2.3 using a set of 24
medium-band filters (FWHM\sim17 nm) at 500-950 nm in GOODS-N. Our observing
strategy is optimized to detect at z>1 the prominent Mg absorption feature at
rest-frame ~280 nm, a distinctive, necessary, and sufficient feature of evolved
stellar populations. Nonetheless, the data quality allow a plethora of studies
on galaxy populations, including Emission Lines Galaxies (ELGs) about which we
have started our first science verification project presented in this
contribution.

Cosmology and Nongalactic Astrophysics