  We study N=1 Supergravity inflation in the context of the braneworld
scenario. Particular attention is paid to the problem of the onset of inflation
at sub-Planckian field values and the ensued inflationary observables. We find
that the so-called $\eta$-problem encountered in supergravity inspired
inflationary models can be solved in the context of the braneworld scenario,
for some range of the parameters involved. Furthermore, we obtain an upper
bound on the scale of the fifth dimension, $M_5 \lsim 10^{-3} M_P$, in case the
inflationary potential is quadratic in the inflaton field, $\phi$. If the
inflationary potential is cubic in $\phi$, consistency with observational data
requires that $M_5 \simeq 9.2 \times 10^{-4} M_P$.
