The preparation of large area conductive transparent ITO films by an ANELVA C-3500 cluster type sputtering system for mass production was carried out. Effects of sputtering parameters, argon and oxygen flow rate, discharge power and substrate temperature on average values and uniformities of deposition rate, specific resistivity, sheet resistance, and transmittance in a substrate were studied by response surface methodology (RSM). Because all desirable properties and uniformities can not be satisfied at the same time, deposition parameters should be optimized. Average values of 2.82 X 10(-4) Ohm cm for specific resistivity and 89.8% for transmittance were obtained within the large area of 340 mm X 440 mm on a 370 mm X 470 mm substrate at a substrate temperature of about 200 degrees C and at a discharge power of 3 kW with a deposition rate of 71 nm min(-1). Other uniformities were +/-2.9% for deposition rate, +/-4.0% for sheet resistance, +/-6.1% for specific resistivity, and +/-1.3% for transmittance at the wave length of 700 nm.