PURPOSE: To increase magnetic attraction without increasing manufacture man- hours and to mount an antenna easily even under an unfavorable environment by providing a permanent magnet on one side of a portable sheet member for which the antenna is attached on the other side.

CONSTITUTION: The antenna 1 is fixed to the portable sheet member 2 by a stud screw 3a projecting through a part of the portable sheet member 2 and a nut 5. The permanent magnets 4 are fixed to a magnetic sheet member 3 by an adhesive material or an adhesive tape. Also, the film sheet 6 of polyester or the like is fixed to the other surface of the permanent magnet 4 by the adhesive material or the like so as to protect the exterior surface of a vehicle. The portable sheet member 2 is freely bent at a part where the permanent magnets 4 are not attached, the permanent magnets 4 are deformable and the magnetic sheet member 3 is beformable as well. Thus, deformation and tight adhesion are performed along a car body shape and fixing to a car body is performed by the magnetic force of the permanent magnets 4.