To provide an ingrown nail correcting device which effectively corrects an ingrown nail by applying stable correcting force for a long time using the effect of a lever.

A lever piece 3 inclined obliquely upward at an angle of 5-25° with respect to the ingrown nail correcting device body 1 is connected to the proximal end of the ingrown nail correcting device body 1 made of a resilient hard synthetic resin and keeping a locking piece part 2, curved into a hook shape to lock the ingrown nail, arranged at the distal end. The connecting part between the ingrown nail correcting device body 1 and the lever piece 3 is formed to serve as a fulcrum part 4. The lever piece 3 is pushed down while the locking piece part 2 locks to the distal end of the ingrown nail and the locking piece part is fixed in such a condition by self-adhesive tapes 6. By doing so, correcting force acting in the direction to raise the ingrown nail is generated at the locking piece part 2 by leverage.