  We report on tunneling spectroscopy measurements using a Scanning Tunneling
Microscope (STM) on the spin triplet superconductor Sr2RuO4. We find a
negligible density of states close to the Fermi level and a fully opened gap
with a value of $\Delta$=0.28 meV, which disappears at T$_c$ = 1.5 K. $\Delta$
is close to the result expected from weak coupling BCS theory
($\Delta_0$=1.76kBT$_c$ = 0.229 meV). Odd parity superconductivity is
associated with a fully isotropic gap without nodes over a significant part of
the Fermi surface.
