In April 2003, the Rationalization in Energy Use Law was revised. Office buildings, schools, hospitals as well as factories are now required to strengthen energy saving measures. Environmental measures and energy saving have become the most significant issue for customers. With cutting edge technology, Tokyo Gas has been improving the efficiency of energy saving equipment/systems such as gas air conditioning, gas cogeneration, and developing “an energy service system” which realizes energy-saving, cost reduction and environmental load reduction as well as realizes environmental measures.