A storage system manages correspondence relationships between physical addresses and logical addresses inside a storage device, as well as logical spaces provided by a plurality of storage devices, and when a determination is made as to whether first data and second data are stored in the same storage device in a case in which the first data and the second data are exchanged inside a logical space, and the determination is found to be affirmative, the storage device replaces the logical address corresponding to the first data with the logical address corresponding to the second data without changing the physical address of the physical area in which the first data is stored and the physical address of the physical area in which the second data is stored.