  We investigate how the mass correction appears in 5-D with Scherk-Schwarz
compactification and clarify whether the KK regularization is reliable method
or not. In the extremely sharp cutoff limit of the 5-D regulator which
preserves 5-D Lorentz invariance, we prove that the one loop correction to the
mass does not depend on the ultraviolet physics for the Scherk-Schwarz breaking
of supersymmetry. This is a unique property of Scherk-Schwarz breaking which is
given by the boundary condition.
