To ensure good operating efficiency and enable uniform bonding of a joint tape by preventing floating of the joint tape.

This tool comprises a main body part 1 and a grip part 2, and the main body part 1 is provided with a guide roller 12 tracing the surface of a joint part, a pressure roller 13 located above the guide roller 12 to press a joint tape against the surface of the joint part, a joint tape guide 14 located at the lower edge of the pressure roller 13, and a holder 15 for the joint tape wound on the rear of the pressure roller 13. The joint tape drawn out from the holder 15 is continuously bonded onto the surface of the joint part as it follows the movement of the main body part 1 and moves in contact with the surface of the pressure roller 13.