  We report the first observation of the Goos-H$\rm \ddot{\textbf{a}}$nchen
shift of a light beam incident on a metal surface. This phenomenon is
particularly interesting because the Goos-H$\rm \ddot{\textbf{a}}$nchen shift
for $p$ polarized light in metals is negative and much bigger than the positive
shift for $s$ polarized light. The experimental result for the measured shifts
as a function of the angle of incidence is in excellent agreement with
theoretical predictions. In an energy-flux interpretation, our measurement
shows the existence of a backward energy flow at the bare metal surface when
this is excited by a $p$ polarized beam of light.
