A map update data supply device and method includes an update map database of per section versions of an update data file, and a request update data extraction unit for extracting a request update section and an update data file. A safeguard update data extraction unit extracts a safeguard update section to safeguard a road network connection between adjacent sections. An integrated data generation unit integrates all versions of the update data file for each extracted request update section and generates a request update integrated data file. The integrated data generation unit integrates, per safeguard update section, versions of the update data file up to the update safeguard version for each extracted safeguard update section, and generates a safeguard update integrated data file. An integrated data supply unit supplies the generated request update integrated data file and the safeguard update integrated data file to a navigation device.