In a storage apparatus, in the case where a data block to be written to a storage medium is a zero data block containing only zero data, a zero data information memory stores zero data identification information indicating that the data block is a zero data block. A control apparatus receives a data block from an access requesting apparatus in association with a write request issued by the access requesting apparatus for writing the data block a specified number of times to a predetermined storage area of the storage medium, and when determining that the data block is a zero data block containing only zero data, sets zero data identification information in the zero data information memory, and when completing the setting of the zero data identification information, sends the access requesting apparatus a completion notice of the writing to the storage medium.