Navigation system and computer-readable recording medium with navigation program

A navigation system (NS) is provided with: an operation section (7) that selects a scheduled route (SL) along which a vehicle is scheduled to move; a system controller (6) that searches for a different route (CL) while the vehicle is moving along the scheduled route (SL), the different route serving to reach a destination for which the mobile unit moves along the scheduled route, and compares the searched different route with the scheduled route for movement of the vehicle from a current position of the vehicle onward; and a display section (8) that gives notice of a comparison result obtained by the controller (6).