Navigation apparatus

The navigation apparatus stores map data used to display map to the user as well as use history information of the map data. The use history information of the map data indicates a Frequency of Use of the map data in the past and so on. When the navigation apparatus need to store new map data during its operation, it detects whether or not unoccupied area is in the storage unit. If unoccupied area is present in the storage unit, the new map data can be stored in the unoccupied area. On the contrary, if no unoccupied area is present in the storage unit, the navigation apparatus erases map data in the storage unit to create unoccupied area based on the use history information of the map data. Therefore, new map data may be stored in the unoccupied area thus created. In this way, the navigation apparatus can efficiently use the storage unit having limited storage capacity to store necessary map data.