This is a bubbling fluidized bed boiler that is highly adaptable to the environment and which operates on recycled waste fuels such as cut tires, wood products, sludge, RPF (refuse paper & plastic fuel) as substitute for fossil fuels. This plant is able to generate high-temperature and high-pressure steam with reduced fossil fuel consumption and lower CO₂ emission. Steel wires contained in tires can be safely and continuously discharged from the fluidized bed furnace without accumulating on the furnace bottom. Further, even when a mixture of different recycled waste fuels is combusted, NO_X and dioxins reduction can be achieved simultaneously by M-STAR (the Mitsubishi multi-stage air re-firing) combustion method, a combustion system(1) patented by Mitsubishi Heavy Industries, Ltd. (MHI). At present, two fluidized bed boilers are commercially operating with recycled waste fuels containing cut tire at Nagoya Pulp Corporation and Mitsubishi Paper Mills Limited.