1. A map information update support device comprising: a characteristic value calculation part that calculates a predetermined characteristic value for each of items of time-series image data of an observation area that is a surrounding area including an observation target feature, the items of time-series image data being acquired by a radar device at different times, respectively; a feature changed area extraction part that extracts a feature changed area from said observation area based on said predetermined characteristic value; a target change candidate area extraction part that synthesizes said feature changed area with pre-stored map information of the observation area, and extracts a change candidate area of an observation target feature; and an output part that outputs the map information including said change candidate area of the observation target feature.