A cable arranging part of the present invention has a fixed shape and comprises a position determining portion, a plurality of cable through holes, and an opening. In a state in which the position determining portion is secured to a position reference portion, the cable arranging part is in a predetermined position on a substrate. The cable through holes become perpendicular to a line of the electrodes and parallel to the substrate in the predetermined position. The opening is provided somewhere midway through the cable through holes and a ground cable through hole. As for the sizes of the cable through holes in a perpendicular direction to the substrate in the predetermined position, the size of the cable through hole on the side where the electrodes are located relative to the opening is greater than the size of the cable through hole on the side opposite to the electrodes.