A storage apparatus includes a storage module, a memory having areas storing data to be copied to the storage device, a saving buffer for temporarily saving the data stored in the areas, a control module for executing receiving a write request including the data to be stored in the storage apparatus, storing the data included in the write request to the storage module and one area, saving the data stored in the one area to the saving buffer when the number of areas which the copying is executed is not less than the threshold value, copying the data stored in the one area to the storage device or writing the saved data stored in the saving buffer to the one area when the number of areas which the copying is executed is less than the threshold value, determining the threshold value in accordance with an amount of the write request.