A controller of a navigation device judges whether or not there are data for which reception has been interrupted, based on data stored in a memory. When there are data for which reception has been interrupted, a distribution request of remaining data of the interrupted reception is transmitted to a center (50) through a data updating unit (310). A memory (55) of the center (50) stores the distribution request of the remaining data for which reception has been interrupted, which is transmitted from the navigation device (110). A controller (57) extracts the remaining data from the memory (55) based on the distribution request stored in the memory (55), and transmits the remaining data to the navigation device (110) through the data updating unit (310). After energy such as fuel is refilled, the user does not need to wait until the completion of the data communication.