The conventional diaphragm gas meter has been in existence now for some 150 years and its design has been extensively rationalized over the years. However, its functionality is limited and cannot be cost-effectively extended to cover areas such as communications. Solid state technology has now developed to the stage where today's single chip microprocessors and custom ASICs (Application Specific Integrated Circuits) can be utilized to produce a fully electronic gas meter based on an ultrasonic flow measurement principle with no moving parts, at a comparable cost to the diaphragm meter, but with better accuracy and stability, as well as offering additional functionality. The development of the ultrasonic measurement cell and the techniques involved are described. The extensive test programme the meter has been subjected to (prior to its submission to the Gas and Oil Measurement Branch (GOMB) of the DTI for approval, which was granted on 14th October 1993) is also described. The manufacturing processes involved in the production of the meter are discussed, with particular emphasis on quality assurance and testing. The future development of the solid state gas meter is considered, especially in the areas of communications, automatic meter reading, temperature compensation and the integration of modules such as electronic cut-off valves and pressure regulators into the meter as part of an overall modular concept.