NOVELTY - A powdered coal thermo-power plant (100) is arranged to burn the composite fuel in which the biomass fuel is set as sub-fuel which is mixed with coal set as main raw material. The thermo-power plant is provided with a bunker (4) in which the composite fuel is accommodated temporarily. A mill (3) is arranged downwards to the bunker to pulverize the composite fuel. The biomass fuel and coal are mixed beforehand to obtain composite fuel, before supplying about 3 mass% or less of biomass fuel to the bunker.    USE - Pulverization method of composite fuel containing coal and biomass fuel which is a plant-derived fuel obtained from waste material, coppiced timber, etc.    ADVANTAGE - Scattering of biomass fuel can be reduced. The supply of composite fuel can be adjusted according to the operating condition of the mill, while mixing the biomass fuel in the ratio of 3 mass% or less with respect to coal. The abnormality caused in the mill can be prevented, and pulverization of composite fuel can be carried out efficiently and stably for a long time.    DETAILED DESCRIPTION - A fine powder supply tube (35) is provided above the mill to circulate the pulverized composite fuel. An air supply tube (36) is provided downwards to the mill to supply air to the mill. A vibration damper (34) is connected to a roller (31) which pulverizes the composite fuel, to suppress the vibration of roller. A motor (37) is arranged to drive the mill. The mixer is equipped with a biomass mixer (20) which mixes the coal and biomass fuel while it conveys the coal. The mixing rate is adjusted with the sending amount of biomass fuel on the screw (12), and the speed of mixer. The mixer is extended from the coal storage area (2) which stores the coal to the bunker. A boiler (5) is arranged to burn the composite fuel after pulverization. An INDEPENDENT CLAIM is included for powdered coal thermo-power plant.    DESCRIPTION OF DRAWING(S) - The drawing shows the schematic view of the powdered coal thermo-power plant.    Coal storage area (2)    Mill (3)    Bunker (4)    Boiler (5)    Screw (12)    Biomass mixer (20)    Roller (31)    Vibration damper (34)    Fine powder supply tube (35)    Air supply tube (36)    Motor (37)    Powdered coal thermo-power plant (100)