PURPOSE: To protect a magnetic recording card which is placed in contact with a ferromagnetic plate from damage and prevent errorneous recording by preventing magnetic leakage by attaching a ferromagnetic plate to the polar surface of a magnet, covering these with a non-magnetic case and by providing a rising shoulder in the tangent direction of ferromagnetic plate.

CONSTITUTION: A through hole 1a is bored to a cylindrical permanent magnet 1 from the one polar surface to the other polar surface, a ferromagnetic plate 3 having a hole connected to the hole 1a is attached to the one polar surface and a ferromagnetic plate 2 which is not provided with hole to the other polar surface. In this case, the hole bored to the ferromagnetic plate 3 is provided with the folded edge collar 4a which may abuts against the internal circumferencial surface of hole 1a and it is folded to the opening edge and is surrounded by the non-magnetic case 4 formed like an inverted saucer having the hook 4b. A ferro- magnetic plate 7 having a ferromagnetic bar 8 at the lower side is located opposing to the magnet 1, the ferromagnetic bar 8 is inserted into the hole 1a under the restriction by the edge collar 4a and is abutted against a ferromagnetic bar 5 provided to the ferromagnetic plate 2.