Using an evaporation system, <TEX>$SiO_2$</TEX> was deposited as a buffer layer between a PET substrate and a ITO layer and then ITO/<TEX>$SiO_2$</TEX>/PET layers were annealed for 1.5 hours at the temperature of <TEX>$180^{\circ}C$</TEX>. Adhesion and electro-optical properties of ITO films were studied with thickness variance of a <TEX>$SiO_2$</TEX> buffer layer. As a result of introduction of the <TEX>$SiO_2$</TEX> buffer layer, sheet resistance and resistivity increased and a ITO film with optimum sheet resistance (<TEX>$529.3{\Omega}/square$</TEX>) for an upper ITO film of resistive type touch panel could be obtained when <TEX>$SiO_2$</TEX> of <TEX>$50{\AA}$</TEX> was deposited. And it was found that ITO films with <TEX>$SiO_2$</TEX> buffer layer have higher transmittance of <TEX>$88{\sim}90%$</TEX> at 550 nm wavelength than ITO films with no buffer layers and the transmittance was enhanced as <TEX>$SiO_2$</TEX> thickness increased from <TEX>$50{\AA}$</TEX> to <TEX>$100{\AA}$</TEX>. Adhesion property of ITO films with <TEX>$SiO_2$</TEX> buffer layers became better than ITO films with no buffer layers and this property was independent of <TEX>$SiO_2$</TEX> thickness variance (<TEX>$50{\sim}100{\AA}$</TEX>). By depositing a <TEX>$SiO_2$</TEX> buffer layer of <TEX>$50{\AA}$</TEX> on the PET substrate and sputtering a ITO thin film on the layer, a ITO film with enhanced adhesion, electro-optical properties could be obtained.