Provided is an incurvated-nails and ingrown-nails correcting device that uses a magnetic force and that is capable of adjusting the space between a magnet and a magnetic sheet that is placed on a nail. The subject device includes a magnetic sheet that is placed on a nail the devices main part that includes a body that is attached to the magnetic sheet by using an adhesive agent or by using the magnetic force of the magnet, an arm that extends outward from the body, a head that is arranged at the edge of the arm, and a joint by which the arm is rotatably connected to the body and by which the head is rotatably connected to the arm and a magnet mounted on the head.
