To prevent break of a waterproof paper in the boundary part of a coil and the scratch in the boundary part of the coil, to facilitate bending in the peripheral direction and also to prevent outward expansion of a part in the peripheral direction of a wavelike formed part after bending.

In a coil corner protector the cross section of which is formed into an approximately L-shape with an outer-peripheral side member 2 covering the outer peripheral surface of the coil 1 of a belt-like body along the peripheral direction and an end face side member 5 which is connected to an outer- peripheral side member 2 through a bent part 3, coveres the end face of the coil along the peripheral direction and also on which the wavelike formed part 4 is provided along the peripheral direction, and is mounted on the boundary part 7 between the outer peripheral surface and end face of the coil, a clearance part 8 where is expanded on a side apart from the boundary part 7 is provided in the position of the bent part 3 so that the inside surface of the bent part 3 is not brought into contact with the boundary part 7.