In a route generating system for an autonomous mobile robot, a plurality of nodes are designated within an area of movement of the robot and an edge is defined between a pair of nodes only if a distance from the one node to the other node is less than a threshold value and there is no obstacle on a line drawn between the one point and the other point. Because the route is generated from a collection of pre-defined edges which are free from obstacles and are selected so as to optimize the generated route, the robot is enabled to travel from the current position to the destination in a safe and optimum fashion. Furthermore, the edges are defined by connecting only those nodes that are relatively close to each other, the candidates of the edges for generating a route can be reduced to a small number and this reduces computational loads. Also, because the route can be selected in a relatively intelligent manner so as to optimize a certain criterion, a clumsy appearance in the movement of the robot can be avoided.