Metals in M33
  The metal content of the spiral galaxy M33 is analyzed through spectroscopic
observations of its emission-line populations, H ii regions and Planetary
Nebulae (PNe): their abundance gradients are identical within the errors. The
2D metallicity map is presented, finding an off-center peak, located in the
southern arm. A chemical evolution model of M33 described by Magrini et al.
(2007a) is updated at the light of recent results on the Schmidt law and the
metallicity gradients.
