WATER CUT-OFF PROCESSING METHOD OF COVERED CONDUCTOR AND WATER CUT-OFF STRUCTURE OF COVERED CONDUCTOR

PROBLEM TO BE SOLVED: To secure a desired water cut-off state by accurately permeating a water cut-off material inside of a covering material of a covered conductor.SOLUTION: A water cut-off processing method of a covered conductor includes forming a concave part 21 on an outer circumferential surface 11A of a conductor 11 over all the circumferential area so as to be spread over an end portion 12a of an electrically insulative covering material 12 in which the conductor 11 is exposed in an extending direction of a covered conductor 13, with respect to the covered conductor 13 including the conductor 11 and the covering material 12 covering the outer circumferential surface 11A of the conductor 11. A flowable water cut-off material 14 is supplied into the concave part 21, and the water cut-off material 14 is permeated inside of the covering material 12. The conductor 11 with which the concave part 21 is formed, includes a diameter reduced portion 21a in which a gap between the conductor 11 and the covering material 12 tends to increase from a covered portion 11a toward an exposed portion 11b in an extending direction of the conductor 11.