An on-vehicle navigation apparatus 50 includes a current location calculator 21 calculating a current location of an own vehicle, a map information database 2 storing map information including road map data, a driving lane specifying section 23 detecting a lane change in response to an operation signal from a winker and specifying a driving lane of the own vehicle, and a guidance-timing controller 24 detecting a turnoff road ahead of the own vehicle in a traveling direction and conducting turnoff road guidance on a driver at a forward position distanced from the detected turnoff road depending on a location of the specified driving lane of the own vehicle.