The utility model relates to a map displaying device. The map displaying device is provided with a temporary storing memory (4) and a depiction memory (6) and comprises a data decompressing processing device (3), a depiction processing device (5) and a display controller (7), wherein the data decompressing processing device (3) reads and decompresses compressed map data by using a block as a unit and stores decompressed map data into the temporary storing memory (4), the compressed map data is stored in data storing media (1) according to blocks, the depiction processing device (5) depicts map data stored in the temporary storing memory (4) into the depiction memory (6), and the display controller (7) displays data in a display area on a display (8) from the depiction area of the depiction memory (6) after the display area is determined. When the temporary storing memory (4) is without data in the display area, the data decompressing processing device (3) reads compressed map data from the data storing media (1) to decompress, and maps using compressed data can be displayed without display delay in a rolling mode.