  We compute the full one-loop radiative corrections (including both weak and
QED corrections) for two processes $e^{+}e^{-}\to Z h^0,H^0 A^{0}$ in the Inert
Higgs Doublet model (IHDM). Up to $O(\alpha_{w})$ and $O(\alpha_{em})$ order,
we use FeynArts/FormCalc to compute the one-loop virtual corrections and
Feynman Diagram Calculation (FDC) to evaluate the real emission, respectively.
Being equipped with these computing tools, we investigate radiative corrections
of new physics for both the degenerate and non-degenerate scenarios with three
typical collision energies of future electron-positron colliders: 250 GeV, 500
GeV, and 1000GeV. By scanning the parameter space of IHDM, we identify the
allowed regions which are consistent with constraints and bounds, from both
theoretical and experimental sides. We find that the radiative corrections of
the IHDM to $e^+ e^- \to Z h^0$ can be sizeable and are within the detection
potentials of future Higgs factories. We also find that the new physics of IHDM
could also be directly detected by observing the process $e^{+}e^{-}\to H^0
A^{0} $ which could have large enough production rate. We propose five
benchmark points and examine their salient features which can serve as physics
targets for future electron-positron colliders, such as CEPC/CLIC/FCC-ee/ILC as
well as for LHC.
