A power feeding device for a slide structure, which includes a link arm turnably provided to one of a slide structure and a fixed structure in a direction to absorb a surplus length of a wire harness, and a harness holding portion provided to a top end side of the link arm. The wire harness is provided from the harness holding portion to a harness fixing portion of the other of the slide structure and the fixed structure, is employed. The link arm is energized by a resilient member. A harness guide is provided along the link arm, and an electric wire portion of the wire harness is provided along the harness guide so as to have a surplus length. A frame-like guide case into which the wire harness is inserted in a turning direction of the link arm is provided.