The high-temperature carbonate fuel cell is an ultra-clean and high-efficiency power generator. It is operated at ~550-650ºC, an optimum temperature range to facilitate fast fuel-cell reaction kinetics, provide high-quality waste heat, and allow use of commercial available materials. Over eighty power plants manufactured by FCE are operating at customer sites throughout the world. The material selections are founded on many years of focused research. Long-term stack endurance as well as field operation results to date show that the baseline construction materials meet the present 5-year endurance goals. Material durability is well understood and solutions are available to further enhance life and durability.