Further insights in expected optical performance of ITO-base MIM metasurfaces can be gained from numerical modeling. For the FDTD simulation, a model of ITO permittivity is essential. In most of TCO works, conductivity and refractive index are discussed. However the conductivity itself is not a constant to the AC conditions encountered at the optical applications, i.e., the high frequency of light is not represented by the DC conductivity. Therefore it is important to consider the Drude model, which is well established for modeling metallic response or free electron behavior at high frequency. By comparison of both models, the conductive and plasma, FDTD simulations of reflection ( ), transmission ( ), Extinction (1 -( + )) are summarised in Fig. . The optical properties of metasurfaces would expected to contain not only the absorption but also the scattering in the 1 -( + ) . As mentioned before, the conductive model cannot However, by using the Drude model, the FDTD results became well matching the experimental data. Figures and show various parameter dependencies set for the both models: 1) conductive (Fig. ) and plasma (Fig. ). In the transparent conductive films, P increases when the conductivity is larger by increasing the carrier density . Therefore, the absorption becomes stronger and transparency decreases. Therefore, the mobility is increased to increase the conductivity to match the experimental observation. When electric conductivity of ITO was increased, the absorption losses especially at the MIR wavelengths were increased too.