Abstract: A sealing structure of a multicore cable includes the multicore cable, a rubber stopper, a cap, and a holder. The multicore cable includes first to fourth electric wires covered with a sheath. The rubber stopper is fitted on an end of the sheath and first to fourth through holes through which the first to the fourth electric wires are passed, respectively. The cap is fitted on the rubber stopper and presses the rubber stopper inward. The holder includes a sheath holding portion for holding the sheath and a cap holding portion for holding the cap.