A slide door harness comprising: a wiring material (10, 12) wired across a slide door slidably provided between a fully closed position and a fully open position with respect to a vehicle body and the vehicle body; a vehicle body-side fixing portion provided in the vehicle body to hold one end of the wiring material (10, 12) below a lower end of an inner surface member of the slide door on a side of the vehicle body in a vertical direction such that the end is allowed to rotate with slide movement of the slide door; and a door-side fixing portion provided on the slide door by being positioned on an opposite side from a side of the vehicle body-side fixing portion with the inner surface member interposed therebetween to hold another end of the wiring material (10, 12) such that the another end is allowed to rotate with slide movement of the slide door, wherein the door-side fixing portion includes a holding portion configured to hold the another end of the wiring material (10, 12) toward a side of the lower end of the inner surface member in the vertical direction, a first rotating shaft configured to allow the holding portion to rotate around a first rotation axis, and a second rotating shaft configured to allow the holding portion and the first rotating shaft to integrally rotate around a second rotation axis intersecting the first rotation axis, and rotation around the first rotation axis by the first rotating shaft and rotation around the second rotation axis by the second rotating shaft are combined so that the another end of the wiring material (10, 12) is rotated downward in the vertical direction with slide movement of the slide door from a side of the fully closed position to a side of the fully open position, the wiring material (10, 12) is positioned across the vehicle body-side fixing portion side and the door-side fixing portion side by straddling the lower end of the inner surface member in the vertical direction, the another end of the wiring material (10, 12) is rotated upward in the vertical direction with slide movement of the slide door from the fully open position side to the fully closed position side, the another end of the wiring material (10, 12) is held above the lower end of the inner surface member in the vertical direction at the fully closed position, and the wiring material (10, 12) is positioned on the door-side fixing portion side of the inner surface member. a wiring material (10, 12) wired across a slide door slidably provided between a fully closed position and a fully open position with respect to a vehicle body and the vehicle body; a vehicle body-side fixing portion provided in the vehicle body to hold one end of the wiring material (10, 12) below a lower end of an inner surface member of the slide door on a side of the vehicle body in a vertical direction such that the end is allowed to rotate with slide movement of the slide door; and a door-side fixing portion provided on the slide door by being positioned on an opposite side from a side of the vehicle body-side fixing portion with the inner surface member interposed therebetween to hold another end of the wiring material (10, 12) such that the another end is allowed to rotate with slide movement of the slide door, wherein the door-side fixing portion includes a holding portion configured to hold the another end of the wiring material (10, 12) toward a side of the lower end of the inner surface member in the vertical direction, a first rotating shaft configured to allow the holding portion to rotate around a first rotation axis, and a second rotating shaft configured to allow the holding portion and the first rotating shaft to integrally rotate around a second rotation axis intersecting the first rotation axis, and a holding portion configured to hold the another end of the wiring material (10, 12) toward a side of the lower end of the inner surface member in the vertical direction, a first rotating shaft configured to allow the holding portion to rotate around a first rotation axis, and a second rotating shaft configured to allow the holding portion and the first rotating shaft to integrally rotate around a second rotation axis intersecting the first rotation axis, and rotation around the first rotation axis by the first rotating shaft and rotation around the second rotation axis by the second rotating shaft are combined so that the another end of the wiring material (10, 12) is rotated downward in the vertical direction with slide movement of the slide door from a side of the fully closed position to a side of the fully open position, the wiring material (10, 12) is positioned across the vehicle body-side fixing portion side and the door-side fixing portion side by straddling the lower end of the inner surface member in the vertical direction, the another end of the wiring material (10, 12) is rotated upward in the vertical direction with slide movement of the slide door from the fully open position side to the fully closed position side, the another end of the wiring material (10, 12) is held above the lower end of the inner surface member in the vertical direction at the fully closed position, and the wiring material (10, 12) is positioned on the door-side fixing portion side of the inner surface member.