An optimum route searching apparatus, method and recording medium make it possible to obtain the optimum cable laying route in a short period of time. The optimum route searching apparatus includes an external storage device for storing search data comprising information related to a route that has a node as a connection point; a simplification device for creating simplified data by extracting information related to a node constituting a branching point, a bending point and a terminal point; a connection information creation device for creating a connection information file of cable laying route based on the simplified data; and a searching device for searching for an optimum cable laying route candidate based on the connection information file. The search termination determination determines search termination for all routes in accordance with the route of interconnected nodes from the start point to either the end point or the dead end having been written to all cards by a card writing device.