A unit setting apparatus sets a unit of distance used in a vehicle. A unit is set, which is indicated by map unit information, as a unit to be used, when a map unit acquisition section has acquired the map unit information. A unit is set, which is indicated by operation unit information, as a unit to be used, when the map unit acquisition section has not acquired the map unit information, and an operation unit acquisition section has acquired operation unit information. A unit is set, which is indicated by sign unit information, as a unit to be used, when the map unit acquisition section has not acquired the map unit information, the operation unit acquisition section has not acquired the operation unit information, and a sign unit acquisition section has acquired the sign unit information.