To provide an auxiliary plate which can be used on all surfaces allowing a push pin to be stuck thereto and, when using a plurality of auxiliary plates, can easily perform the attaching and detaching of a larger notice, by using the magnet, such as a poster with respect to the surface not being attracted by a magnet without paying regard to scratch or the like.

(1) The auxiliary plate 1 which can be attached to the magnet having a hole opened at the center so as to be attached thereto with one piece of nail, screw or push pin is disposed. (2) When being fastened by the nail or the push pin, a seating is disposed in order to improve the adhesiveness between the nail or the push pin, and the plate 1. (3) A plastic protective seal formed as a sticker is attached to the auxiliary plate 1 to be attracted to the magnet after being fastened with the nail, the screw or the push pin.