Through power generation tests using a fuel cell evaluation equipment, we can obtain not only catalyst metal specific surface area and catalyst activity, but also various information on MEA. Furthermore, by incorporating mathematical models such as the 1-D model (transmission line model), it is possible to concretely understand the causes of power generation loss. Analysis of drain water and exhaust gas during the durability tests provides information on degradation factors of the catalyst metal, the polymer electrolyte membrane and carbon catalyst supports.