  The Standard Model Higgs boson with large nonminimal coupling to the
gravitational curvature can drive cosmological inflation. We study this type of
inflationary scenario in the context of supersymmetric grand unification and
point out that it is naturally implemented in the {\em minimal} supersymmetric
SU(5) model, and hence virtually in any GUT models. It is shown that with an
appropriate K\"{a}hler potential the inflaton trajectory settles down to the
Standard Model vacuum at the end of the slow roll. The predicted cosmological
parameters are also consistent with the 7-year WMAP data.
