Indium tin oxide films with high conductivity and transparency were successfully prepared by evaporating an alloy of indium and tin covered with In2O3 powder. At room temperature the films have high carrier mobilities of about 60 cm2 V-1 s-1. Conductivities as high as 5 × 103 Ω-1 cm-1 and transmittance values of greater than 90% in the visible region of light were obtained. The carrier mobility was found to be inversely proportional to temperature in the high temperature range and independent of temperature in the low temperature range. The temperature dependence of the carrier conductivity indicated that the carrier excitation energy was less than 8.6 × 10-6 eV. Mössbauer spectroscopy showed that the tin in all the high quality films was tetravalent.