Destination information, which includes as a retrieval condition an address of a destination spot, is received externally. Under the received retrieval condition of the address, a spot retrieval is performed with reference to own map data to thereby acquire a specified spot and second coordinates data indicating the specified spot. When the received destination information includes first coordinates data indicating the destination spot, it is determined whether a direct distance between a first spot indicated by the first coordinates data and a second spot indicated by the second coordinates data is equal to or less than a threshold value. When the direct distance is equal or less than the threshold value, the second spot is displayed as a destination on a map. When the direct distance is greater than the threshold value, the first spot is displayed as a destination on a map.