An anticorrosion sleeve including a resin sleeve and a metal sleeve tightly received in the resin sleeve. The metal sleeve has a gradually expanding outer diameter thereof toward one circular edge thereof in a tapered shape in cross section so that the metal sleeve expands the resin sleeve in diameter when the metal sleeve is inserted into the resin sleeve. The resin sleeve includes a large-diameter portion and a small-diameter portion. The metal sleeve includes an engagement end portion, an intermediate portion, and a tapered end portion in that order. The outer circumference of the engagement end portion of the metal sleeve is engaged beforehand with a step between the inner circumferences of the large-diameter portion and the small-diameter portion of the resin sleeve.