Device, method and update server for automatically updating navigation system

An automatic navigation-system update device, comprising:

• a storage unit including a first storage module and a second storage module each of which stores map data and map version information, wherein the map data of the first storage module and the map data of the second storage module are initially identical to each other;
• a communication unit configured to transmit the map version information extracted from the storage unit to an update server and to receive, from the update server, differential data of map data based on a difference between the map version information and latest map version information;
• and
• a control unit configured to guide a route on the basis of the map data stored in the first storage module and to update the map data stored in the second storage module by reflecting the differential data, and the control unit further configured to copy all the updated map data of the second storage module into the first storage module to synchronize the map data of the first storage module or copy the differential data stored in the second storage module into the first storage module to update and synchronize the map data of the first storage module,
• wherein the control unit guides the route only based on the map data stored in the second storage module when an operation of the first storage module is stopped.