  We present here some of the first results we have obtained on the study of
the optical spectra of Spitzer/MIPS 24 micron-selected galaxies in the
  COSMOS field. This is part of a series of studies we are conducting to
analyse the optical spectral properties of mid-infrared (mid-IR) galaxies with
different
  IR luminosities up to high redshifts. The results shown here correspond to
the brightest S(24 micron)>2 mJy IR galaxy population at z<1.
