A process and apparatus for producing an In-O or In-Sn-O based transparent conductive film by a sputtering process is provided. The sputtering voltage is kept constant at 350V or less by maintaining the intensity of the magnetic field on the surface of the target at 400 Oe or greater. The apparatus contains a vacuum chamber wherein the substrate and target are mounted in opposite to each other. An electromagnet, used for adjusting the intensity of the magnetic field is located on the rear surface of the target. Additionally provided is a controller for the electric current supplied to the electromagnet. The controller is also connected to a DC power supply for the electromagnet.