To provide a T-nut obtaining high sealing performance and suppressing the displacement and fall-off of a sealing member due to the contact of a guide pin or a bolt, thereby restraining molten resin, a coating material, or the like from intruding into a shaft part of the T-nut.

The T-nut 1 includes the cylindrical shaft part 4, and a flange part 5 extended outward from the first end of the shaft part 4. The shaft part 4 is opened at both ends and provided with an internal thread 4c on the inner peripheral surface. The T-nut 1 also includes a sealing member 3 made of elastic resin to seal the first end side opening of the shaft part 4. The sealing member 3 includes a cylindrical part 3a brought into close contact with the inner peripheral surface of the shaft part 4 and opened on the first end side, and a dome-like cover part 3b continuous with the second end side edge of the cylindrical part 3a so that an apex faces the second end side. The cylindrical part 3a includes, on the outer peripheral surface, a projection 3c of external thread shape for sealing the root space of the internal thread 4c. With the first end side placed on the upper side, the upper side edge of the sealing member 3 is located flush with the upper side end face 5a of the flange part 5 or below the end face 5a.