For the purpose of suppressing decrease of a deduplication rate in a storage system, a storage system according to the present invention includes: a data buffer; a dividing unit configured to generate divided data by dividing data inputted into the data buffer; and a storage processing unit configured to store the divided data into a storage device while eliminating duplicate storage. The dividing unit is configured to generate the divided data by dividing the data inputted into the data buffer by a preset division standard based on the content of the data and also divide, by the division standard, connected data that residual data being left without being divided by the division standard and continuing data continuing to the residual data and being inputted in the data buffer are connected.