MAP UPDATE DEVICE AND STORAGE MEDIUM

A server includes a feature point position estimation section that estimates positions of feature points of a plurality of respective input maps if a position correction section has failed in position correction for an input map, an accumulated data generation section that accumulates the positions of the feature points of the plurality of respective input maps to generate accumulated data, a convergence determination section that determines whether the positions of the feature points have converged based on the accumulated data, a difference data generation section that generates, if it is determined that the positions of the feature points have converged, difference data from the positions of the feature points that have converged, and a difference data reflection section that reflects the difference data in the reference map to update the reference map.