PURPOSE: To omit hardware for display of only natural pictures by displaying a natural picture having a large data volume together on a display means on which map data and guide information data are displayed.

CONSTITUTION: The natural picture digital signal which is digitized and compressed and is recorded on a recording medium is read out by a read means (CD-ROM drive) 6 and is decoded by soft operation of an operation control means (ROM) 3. The natural picture is drawn and displayed on a display device by a display means (video RAM) 10 in the same manner as graphic drawing after bit reduction. Since the compressed natural picture digital signal is decoded and the bit processing is performed by arithmetic processing based on software in this case, hardware like a decoder only for natural picture is omitted, and the cost is reduced and the device is miniaturized.