A data writing control device enables quickly writing data to optical discs. A reading process unit 62a, 62b reads data in predetermined read units from a storage device (hard disk drive 14) that has a head and stores the data. A storage unit (buffers 63a and 63b) has a storage area for storing the read units of data read by the reading process unit 62a, 62b. A writing process unit 64a, 64b acquires data stored in the storage area of the storage unit in write units, which are smaller than the read units, and supplies the acquired write units of data to an optical disc drive which is connected as a peripheral device.