A vehicle control device 50, a controller 100, an inverter control device 30 and a steering control device 32 constitute a control device that executes control to give a yaw moment to a vehicle 1 so as to make the vehicle 1 travel while meandering around the center of trolley wires 3R and 3L based on image information acquired by a camera 15. The control device converts an image acquired by the camera 15 into coordinate information, calculates at least one representative point of the vehicle 1 and at least one target point situated on the trolley wire 3R/3L based on the coordinate information, sets a fluctuating point which fluctuates with reference to the target point, and executes control to give a yaw moment to the vehicle 1 so that the representative point approaches the fluctuating point. With this configuration, uneven wear of the sliders can be prevented and the operating load on the driver during the trolley traveling can be lightened considerably.