To provide a margin protector and a margin protector set providing fanciness by fixing the protector to the margin of a plate-like article such as a file, a binder, a holder, a notebook, a menu and enhancing utility by making protector hard to slide.

A corner fitting 1 has a corner fitting body 10 with an approximately U-shape cross section having a bottom face 10c facing the margin 3 of the teo-folded menu 2 and side faces 10d at both sides of the same and having openings 10e at the bottom face 10c and slipping preventing members 11 held at the bottom face at 10c and protruding from the openings 10e.