  The slow roll inflation requires an extremely flat inflaton potential. The
supersymmetry (SUSY) is not only motivated from the gauge hierarchy problem,
but also from stabilizing that flatness of the inflaton potential against
radiative corrections. However, it has been known that the Planck suppressed
higher order terms in the K\"ahler potential receive large radiative
corrections loosing the required flatness in the N = 1 supergravity. We propose
to impose a global N = 2 SUSY on the inflaton sector. What we find is that the
N = 2 SUSY Abelian gauge theory is exactly the same as the desired hybrid
inflation model. The flat potential at the tree level is not our choice of
parameters but a result of the symmetry. We further introduce a cut-off scale
of the theory which is lower than the Planck scale. This lower cut-off scale
suppresses the supergravity loop corrections to the flat inflaton potential.
