To intuitively and concisely edit a guidance route according to a user's intention.

While a virtual present position 154 is advancing little by little on the guidance route 153 to be set between a destination 152 and a starting place 151, a simulation by which a navigation screen expressing the guidance route 153 and the position 154 on a map around the position 154 at a point of time is displayed at each point of time is performed (a). When a user's voice uttering 'Turn to the left' is detected at a point of time when the position 154 advances to a position shown in the figure on the guidance route 153 during the simulation, a new guidance route 156 which turns to the left in a next crossing 155 capable of being turned to the left as viewed in a traveling direction from the position 154 at the point of time is set (b). A simulation according to the new guidance route 156 is continued from the position 154 at this point of time.