The theory of cathode sputtering with the advantages and limitations in the application of this process is discussed, followed by a description of the commercial equipment and methods for applying gold electrode surfaces to diaphragms of certain types of microphones. By proper design of the vacuum chamber and the inside parts, a fairly uniform discharge current density and a uniform deposit is obtained. A constant sputtering rate is produced by the use of a bleeder valve which maintains a proper residual pressure. Adherence and continuity are obtained by the use of a special cleaning process. An extensive bibliography on cathode sputtering is included.