  We discuss a five dimensional inflationary scenario based on a supersymmetric
SO(10) model compactified on $S^1/(Z_2\times Z_2')$. Inflation is implemented
through scalar potentials on four dimensional branes, and a brane-localized
Einstein-Hilbert term is essential to make both brane vacuum energies positive
during inflation. The orbifold boundary conditions break the SO(10) gauge
symmetry to $SU(4)_c\times SU(2)_L\times SU(2)_R$ ($\equiv H$). The
inflationary scenario yields $\delta T/T\propto (M/M_{\rm Planck})^2$, which
fixes $M$, the symmetry breaking scale of $H$ to be close to the SUSY GUT scale
of $10^{16}$ GeV. The scalar spectral index $n$ is $0.98-0.99$, and the tensor
to scalar ratio $r$ is $\lapproxeq 10^{-4}$. The inflaton decay into the
lightest right handed neutrinos yields the observed baryon asymmetry via
leptogenesis.
