An electricity feeding device used in conjunction with a vehicle having a slide door mounted on the vehicle body includes a flexible conductive part having a curved portion, with the curved portion being displaced with sliding movement of the slide door for alternately opening and closing an opening area formed in a side wall of a vehicle body. The flexible conductive part also includes a wire providing an electrical connection between components in the slide door and the vehicle body. In addition, an insulating member covers the wire, and a steel-made belt extends along the insulating member so that the insulating member is mounted on the belt. The belt has a vertical cross-section with respect to a sliding direction of the slide door that possesses a concave surface.