To provide a keeper for a dental magnetic attachment which allows fusion joining of a root cap by casting to the keeper without the intervention of an oxidized film to the boundary of the keeper and the cast root cap to be cast joined and does not give rise to crevice corrosion in the cast joint part even when the keeper is used for a long period by being mounted within the oral cavity.

The keeper which allows ideal cast joining by applying a coating of a high-temperature oxidation resistant noble metal to the outermost shell surface of the keeper composed of a magnetic material and fusing the keeper surface and the cast root cap with the molten metal at the boundary in casting is provided. When the root cap of the keeper is cast by a lost wax method used in dental casting, the high-temperature oxidation resistant noble metal coating of the keeper and the cast molten metal are fused at the boundary.