  We present the abundance analysis for a sample of 18 red giant branch stars
in the metal-poor globular cluster NGC 4147 based on medium and high resolution
spectra. This is the first extensive spectroscopic study of this cluster. We
derive abundances of C, N, O, Na, Mg, Al, Si, Ca, Ti, Cr, Fe, Ni, Y, Ba, and
Eu. We find a metallicity of [Fe/H]=-1.84+-0.02 and an alpha-enhancement of
+0.38+-0.05 (errors on the mean), typical of halo globular clusters in this
metallicity regime. A significant spread is observed in the abundances of light
elements C, N, O, Na, and Al. In particular we found a Na-O anti-correlation
and Na-Al correlation. The cluster contains only 15% of stars that belong to
the first generation (Na-poor and O-rich). This implies that it suffered a
severe mass loss during its lifetime. Its [Ca/Fe] and [Ti/Fe] mean values agree
better with the Galactic Halo trend than with the trend of extragalactic
environments at the cluster metallicity. This possibly suggests that NGC 4147
is a genuine Galactic object at odd with what claimed by some author that
proposed the cluster to be member of the Sagittarius dwarf galaxy. A
anti-relation between the light s-process element Y and Na may also be present.
