To present a map picture of a geographical area suited to use conditions whether a map displaying device is used as portable one or as on- vehicle one.

When a switching operation to an on-vehicle mode or to a portable mode is performed on an operation part 5, a use mode switching part 7 switches a depiction part 10 to the on-vehicle mode or to the portable mode. Based on a present position detected by a GPS receiving part 2 and modified by a map matching part 8, the depiction part 10 performs depiction. As to the on-vehicle mode, by using data of a small-scale map stored in a map memory part 4, map pictures of a geographically large area including the present position are depicted together with a present position mark. As to the portable mode, by using data of a large-scale map, detailed map pictures of a geographically small area including the present position are depicted together with a present position mark. The map pictures are converted into image signals, outputted to a display part 3, and displayed on a screen.