To provide an easily dismantled fastening component capable of using an improving means of a working property utilizing magnetism by giving magnetism.

In the fastening component having a pipe-shaped shaft made of a shape memory material and fastening and retaining a plurality of members, a magnetic body sheet is installed on an inner wall surface of the shaft. A core material has high rigidity at a normal temperature level, and has low rigidity by softening at a temperature level beyond a transforming temperature of the shape memory material as the material of the shaft. The core material is preferably filled up in a cylindrical inside of the magnetic body sheet.