The use of conductive metal oxide (CMO) films as supporting layers for ATR-SEIRAS is treated theoretically and experimentally. The greater mid-infrared transparency of thin layers of indium zinc oxide (IZO), as compared to metals, is verified through IR reflectivity measurements and the Drude model. IZO layers sputtered on our Specialized 1 ATR Crystals are found to have a thin surface layer with slightly different plasma frequency and electronic scattering time compared to the bulk material.