Map data updating method and map data updating terminal

In order to quickly update map data in region units without generation of contradiction to adjacent non-updated regions after the updating, under map data updating, time and date of updating of update region of a terminal is obtained with designation of a region as the update object used as a trigger, a mesh ID on the external boundary of the partial update region is obtained, and the differential updating data ID of the updated differential updating data is also obtained from the terminal. The partial updating data and differential updating data required for updating of the designated region of the terminal are selected from the information obtained above and these selected data are applied to the map data of terminal. When updating is conducted using the partial updating data and differential updating data, the time and date of updating of the relevant partial update region ID are changed and the differential updating data ID is registered to the differential management data.