To remarkably facilitate a fitting work of a sleeve to a wall body while securing a cut-off effect to water immersing from the outside when an electric wire and a pipeline are arranged over the inside and the outside of the wall body.

A sleeve 5 which is arranged between through holes 1a, 3a between an outer wall plate 1 and a side plate 3 has: a cylindrical sleeve body 51; a pawl part 52 which is arranged at an end of the side plate 3 and projected toward the side plate 3 and engaged into the rear surface of the side plate 3 via the through hole 3a; and an annular flange part 53 which extends outward of a radial direction of the sleeve body 51 at an end of the side of the side plate 3 of the sleeve body 51, and a cut-off material 14 which has a hole part 14a into which the sleeve body 51 can be inserted for the through hole 3a of the side plate 3 and a through hole 8a of a waterproof sheet 8, pressed and held by the flange part 53 is provided between the waterproof sheet 8 arranged on the front surface side of the side plate 3 and the flange part 53.