Large frame gas turbines for power generation have been developed with more emphasis on improving their thermal efficiency based on the technology for raising to higher temperatures supported by such component technology as cooling and materials. Mitsubishi Heavy Industries, Ltd. (MHI) developed a 1,100°C class D-type gas turbine in the 1980s and constructed the world's first successful large-scale combined cycle power plant. Since then, MHI has developed the F-type and G-type gas turbines with even higher turbine inlet temperature and has delivered many of them in Japan as well as overseas while accumulating successful commercial operations. MHI has constantly improved these gas turbines, adding to their successful operation. Now, MHI is participating in a national project to promote the development of component technology for the next generation 1,700°C class gas turbine, whose thermal efficiency will be improved significantly by raising the turbine inlet temperature.