A remote controller enables a user to manipulate behavior of a robot so that the robot does not stray away from a given area and also avoids contact with an object. If a route designated by the user satisfies a stable movement requirement, a first command signal is transmitted from the remote controller to the robot. By doing so, it is possible to move the robot according to the designated route. On the other hand, if the route designated by the user does not satisfy the stable movement requirement, the first command signal is not transmitted from the remote controller to the robot. Therefore, it is possible to stop the robot from moving according to the designated route, and further to avoid the situation where the robot strays away from the designated region, or comes into contact with the object.