A navigation apparatus is obtained that can reduce as much as possible to blank interval during the navigation even when a route deviation has occurred. In order to structure a navigation apparatus that includes a guided vehicle position determining portion 3c that finds the position of a guided vehicle and a recommended route searching portion 3i that searches for a recommended route to a destination point, a problem condition identifying portion 3f is provided that identifies the presence or absence of a problem condition that makes the travel along the recommended route Ro difficult when viewed in terms of the current condition of the guided vehicle with respect to the recommended route Ro forward travel side of the position of the guided vehicle, and a route deviation plan portion 3h is provided that sets a point that the guided vehicle is anticipated to reach under the presence of the problem condition to the starting point, activates the recommended route searching portion 3i, and searches for a new recommended route Rn from the starting point to a destination point in the case in which the problem condition identifying portion 3f has identified that a problem condition is present.