Kimitsu Cooperative Thermal Power Company, Inc. Unit No. 5 is the world's first BFG-firing combined cycle plant featuring high efficiency and large capacity with F series gas turbine. Mitsubishi Heavy Industries, Ltd. (MHI) has developed and installed the principal devices including gas turbine, steam turbine, gas cooler, condenser, and distributed control system (DCS). MHI has been researching and developing BFG-firing gas turbines for many years, and has built various BFG-firing combined cycle plants with D series gas turbine. This paper introduces the latest technology established and verified for the first time in the world in this power plant.