Abstract: The invention provides a combustion apparatus and a combustion method capable of ashing matter to be combusted inside a combustion chamber efficiently without providing a device such as an unburned combustibles measurement device and without varying the direction of injection of air into the combustion chamber. The powder fuel combustion apparatus 1 includes a fuel supply device 10, a primary combustion chamber 20, a secondary combustion chamber 50, an air supply/ash discharge device 32, and a cyclone dust collector 60. An inclined portion 23a is formed at a bottom portion 23 of the primary combustion chamber 20, and the inclined portion 23a includes bottom portion air supply ports 31 and an air supply/ash discharge device 32. The air supply/ash discharge device 32 includes a bottom portion air injection nozzle 34 and an ash delivery device 35.