1. A control device of a storage system that comprises a plurality types of storage devices, comprising: a memory which stores a data management information regarding data which is stored in the storage devices; a CPU coupled to the memory; an input device, coupled to the CPU, which receives an input information, the input information including at least a size and an archive deadline of data which is stored in the storage devices; wherein the data management information includes a write threshold value regarding one type of storage devices, the write threshold value indicating a write limit number to the one type of storage devices, wherein the CPU selects a storage device which stores data corresponding to the information which is input to the input device, on a basis of an archiving cost which is calculated by an arising bit cost of a new volume of the storage devices and the costs of performing data migration from existing volume to the new volume of the storage devices, the input information, and the data management information which is stored in the memory, a cost target item and a bit cost of the cost target item, wherein the CPU stores to the selected storage device, the data corresponding to the information which is input to the input device, and wherein the CPU registers to the data management information in the memory, at least one of the information which is input to the input device.