  We study the metallicity properties of galaxies in the zCOSMOS sample between
0.2<z<0.8. At z<0.46, where Ha and [NII] are detected, we find the same
dependence of metallicity on stellar mass and Star Formation Rate (SFR), the
Fundamental Metallicity Relation, found by Mannucci et al. (2010) in SDSS
galaxies on a similar redshift range. We extend this relation to higher
redshift, 0.49<z<0.8 where the R23 metallicity index can be measured in our
data, finding no evidence for evolution, and a metallicity scatter around the
relation of about 0.16 dex. This result confirms, with a much higher level of
significance with respect to previous works, the absence of evolution of the
FMR during the last half of cosmic history.
