To provide a penetration part forming member of a wiring or piping material and a device using the same, capable of coping with the situation even if a wall thickness is different with every construction site, by fixing a joint and an extraction port forming tool to the penetration part forming member, in the penetration part forming member arranged in a through-hole of a wall.

This penetration part forming member 100 includes a cylinder part 10 for inserting the wiring or piping material inside, and one side member 20 arranged on the base end side being one side of the wall of the cylinder part 10 arranged in the through-hole and arranging the cylinder part 10 in the through-hole. The cylinder part 10 can be cut on the tip side for changing the extension length of the cylinder body toward the other side of the wall, and the wiring or piping material in the cylinder part is connected or inserted, and a machine screw prepared hole 13a capable of installing a machine screw of the other side member (a joint 30) arranged on the other side of the wall, is arranged on a tip surface 14 of the cylinder part 10. The machine screw prepared hole 13a is also formed along the longitudinal direction of the cylinder part 10 so as to also appear on a cutting surface 14a of cutting.