To facilitate the manufacture of a damper using a manufacturing mold by connecting mass bodies to a hub via elastic bodies made of rubber-like elastic material, and providing a pouring port of rubber material forming the elastic bodies on a mass body on dampers employing the mass bodies bonded with the vulcanized elastic bodies.

When manufacturing a torsional damper in which first to third mass bodies 5, 6, 7 are connected to a hub 1 via first to third elastic bodies 2, 3, 4 respectively, using a manufacturing mold, the hub 1 and the respective mass bodies 5-7 are placed in their position of a cavity, and the mold is closed first. Next, the first mass body 5 is fixed to its position by aligning and jointing a pouring port 8 provided on it to the protruded part provided on the inner wall of the cavity. When rubber material is filled in the cavity inside the mold, the rubber material flows from the pouring port 8 through to respective through- holes 9, and concurrently the rubber material is poured through a secondary pouring port 10 provided on the hub 1. Then, the rubber material is vulcanized and bonded to each of the elastic bodies 2, 3, 4 to complete a damper.