Image and sound data stored in an optical disc unit having an medium auto-changer mechanism are read out and temporarily stored in a hard disk unit, after then supplied to a user's terminal unit via a memory which serves as an output buffer. The image and sound data are stored in the memory, by compressing and a time length required to read out the data is shorter than a reproduction time in the user's terminal unit, and therefore plural data are read out by a difference between a readout time and the reproduction time. Since write operation to the hard disk unit and readout operation from the hard disk unit to write to the main memory 3 are simultaneously carried out, plural hard disk units are disposed and accessed in parallel. Moreover, a unit of data in write operation is larger than a unit of data in readout operation in the hard disk unit.