Provided is a finely-powdered coal burning boiler, which reduces an air-excess ratio thereby to reduce the emission of unburned contents such as CO. The finely-powdered coal burning boiler comprises finely-powdered coal feed measuring means (51) for measuring the feeding rates of the finely-powdered coal to be conveyed through coal feeding pipes (43), individually, and control means (66) for calculating the burning air feeding rates to match the finely-powdered coal feeding rates thereby to send a control command signal to burning air feed adjusting means (64), so that a burner air ratio set by burner air ratio setting means may be kept on the basis of both the finely-powered coal feeding rate, which is measured by the finely-powdered coal feed measuring means (51), and the burning air feeding rate, which is measured by the burning air feeding rate measuring means and fed to a finely-powdered coal burner (61) connected to the coal feeding pipes (43).