A path guidance method for autonomous mobile device, by which a directional wireless reception unit, arranged on the autonomous mobile device, is enabled to receive a radio wave guidance signal issued by a call unit while the direction pointing to the call unit can be determined with respect to the intensity and direction of the received radio wave guidance signal, and thus the autonomous mobile device is directed to move toward the pointing direction until the autonomous mobile device reaches a location specified by the call unit. In a preferred aspect, the autonomous mobile device is determined to be not far from the call unit when the intensity of the radio wave guidance signal, received by the directional wireless reception unit, is larger than a predefined value.