An updated part of map data is delivered while suppressing unwanted
communication traffic and preventing contradiction in the updated map. A
map delivering server (10) comprises a map data storage section (102)
storing link data including the update dates and times and update
infection range for each link, a network IF section (101) for receiving
from a navigation terminal (20) a map delivery request containing the
requested area of map delivery and the previous request data and time of
map delivery of the requested area, and a map element search section
(103) for searching the map data storage section (102) for the link data
associated with the update infection range including the link at least a
part of which belongs to the requested area of the map delivery request
and associated with the update date and time later than the previous
request date and time contained in the map delivery request. The link
data found by the map element search section (103) is sent to the
navigation terminal (20) through the network IF section (101).