A screw attachment (10, 10', 10'') disposed around a fastening piece (17) secured to a main fastening body (25a), the screw attachment sandwiched between a head (17b) of the fastening piece and a securing object (22) so that the screw attachment bears a securing force of the fastening piece to press the securing object. The screw attachment includes a pair of arms (12, 13) made of a shape restoring material. Each arm has a fore end, and the fore ends are joined to each other with an adhesive material that is softened when heated. The arms expands radially such that the screw attachment is released from the head of the fastening piece when heat or force is applied to the arms.