A pulverized coal burning boiler comprising: milling means which generate pulverized coal by milling supplied coal; coal feeding pipes which are arranged in such a manner that a plurality of coal feeding pipes are connected to one milling means and through which the pulverized coal is airflow-conveyed by primary air; pulverized coal burners which are connected to front end sides of the coal feeding pipes respectively and which have pulverized coal nozzles disposed so as to face into a furnace; combustion air supply means which supply combustion air other than the primary air to the pulverized coal burners individually; combustion air supply amount measuring means which measure the supply amounts of the combustion air supplied by the combustion air supply means individually; combustion air supply amount adjusting means which adjust the supply amounts of the combustion air; and burner air ratio setting means which set burner air ratios; wherein pulverized coal milled and generated by the milling means is distributed to the coal feeding pipes, jetted from the pulverized coal nozzles into the furnace and burned under supply of the combustion air; the pulverized coal burning boiler further comprising: pulverized coal supply amount measuring means which individually measure the supply amounts of pulverized coal conveyed through the coal feeding pipes respectively; and further comprising an air supply amount control means, characterized in that the air supply amount control means, based on the supply amounts of pulverized coal measured by the pulverized coal supply amount measuring means, detects a deviation of the flow rate of the pulverized coal conveyed by each coal feeding pipe from an average flow rate of pulverized coal conveyed by all the coal feeding pipes; calculates the amount of supplied combustion air corresponding to the amount of pulverized coal based on the deviation individually for each pulverized coal burner so that the air ratio set by the burner air ratio setting means can be kept; and transmits a control signal to each combustion air supply amount adjusting means to thereby adjust the amount of combustion air supplied to each pulverized coal burner individually. milling means which generate pulverized coal by milling supplied coal; coal feeding pipes which are arranged in such a manner that a plurality of coal feeding pipes are connected to one milling means and through which the pulverized coal is airflow-conveyed by primary air; pulverized coal burners which are connected to front end sides of the coal feeding pipes respectively and which have pulverized coal nozzles disposed so as to face into a furnace; combustion air supply means which supply combustion air other than the primary air to the pulverized coal burners individually; combustion air supply amount measuring means which measure the supply amounts of the combustion air supplied by the combustion air supply means individually; combustion air supply amount adjusting means which adjust the supply amounts of the combustion air; and burner air ratio setting means which set burner air ratios; wherein pulverized coal milled and generated by the milling means is distributed to the coal feeding pipes, jetted from the pulverized coal nozzles into the furnace and burned under supply of the combustion air; the pulverized coal burning boiler further comprising: pulverized coal supply amount measuring means which individually measure the supply amounts of pulverized coal conveyed through the coal feeding pipes respectively; and further comprising an air supply amount control means, characterized in that the air supply amount control means, based on the supply amounts of pulverized coal measured by the pulverized coal supply amount measuring means, detects a deviation of the flow rate of the pulverized coal conveyed by each coal feeding pipe from an average flow rate of pulverized coal conveyed by all the coal feeding pipes; calculates the amount of supplied combustion air corresponding to the amount of pulverized coal based on the deviation individually for each pulverized coal burner so that the air ratio set by the burner air ratio setting means can be kept; and transmits a control signal to each combustion air supply amount adjusting means to thereby adjust the amount of combustion air supplied to each pulverized coal burner individually. pulverized coal supply amount measuring means which individually measure the supply amounts of pulverized coal conveyed through the coal feeding pipes respectively; and further comprising an air supply amount control means, characterized in that the air supply amount control means, based on the supply amounts of pulverized coal measured by the pulverized coal supply amount measuring means, detects a deviation of the flow rate of the pulverized coal conveyed by each coal feeding pipe from an average flow rate of pulverized coal conveyed by all the coal feeding pipes; calculates the amount of supplied combustion air corresponding to the amount of pulverized coal based on the deviation individually for each pulverized coal burner so that the air ratio set by the burner air ratio setting means can be kept; and transmits a control signal to each combustion air supply amount adjusting means to thereby adjust the amount of combustion air supplied to each pulverized coal burner individually.