To enable a user to easily obtain the change of information before and after updating map data.

A map information display means comprises: a first storage means storing at least a part of a fist map data; a second storage means storing second map data different from the first map data; a difference information acquisition means acquiring difference information between the first map data and the second map data; and a symbol display means displaying, in a specific form, a symbol corresponding to the difference information acquired by the difference information acquisition means.

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