The transmittance enhancement of amorphous oxide-metal-amorphous oxide multilayer electrode has been performed by controlling oxide layer thickness. Layer thickness of SiInZnO/Ag/SiInZnO (SIZO OMO) has been simulated and optimized to enhance the transmittance without any sacrificing the sheet resistance. The refractive index and extinction coefficient of SIZO maintained about 2.1 and 0. As increasing top/bottom amorphous oxide SIZO layer thickness in SIZO OMO structure, maximum transmittance wavelength shifted steadily to longer wavelength region. In order to get the optimized condition of SIZO OMO, we simulated layer thickness by using Essential Macleod Program (EMP). The sheet resistance was maintained to be about 6–8 Ω/sq despite of increasing top/bottom SIZO layer. By optimizing top/bottom SIZO layer thickness, 50 nm amorphous oxide thick SIZO OMO showed transmittance of 96.67% at 550 nm, sheet resistance of 6.41 Ω/sq and figure of merit of 11.11 × 10⁻²Ω⁻¹.