A stream data control server includes: a processable flow rate managing unit which manages a processable flow rate corresponding to an amount of data per unit time, which can be processed in each of storage units serving as storing destinations; a classified data flow rate managing unit which manages a data flow rate corresponding to an amount of data processed per unit time for each class of data to which a data priority is attached; and a storing destination control unit which controls the storing destinations of respective data based upon the processable flow rate of each of the storage units and the data flow rate for each class in such a manner that the data having higher data priorities are stored in the storage units having higher priorities within a range of the processable flow rate of each of the storage units.