A route guidance device configured so as to be freely attachable and detachable with respect to an in-vehicle device includes a route acquiring part that acquires a vehicle route calculated based on vehicle map data and acquires a pedestrian route calculated based on the pedestrian map data; and a display that outputs the vehicle route and the pedestrian route acquired by the route acquiring part. The route acquiring part, when the route guidance device has been detached from the in-vehicle device, acquires a pedestrian route calculated based on a destination having been set to acquire the vehicle route before detachment, or when the route guidance device has been attached to the in-vehicle device, acquires a vehicle route calculated based on a destination having been set to acquire the pedestrian route before attachment.