The present invention provides a corrector for a deformed nail capable of being easily inserted into near a root of the nail without giving pain to a patient when attaching the corrector even for a serious ingrown nail which is significantly deformed and curved or a deformed nail having an irregular shape on a lateral edge. Thus, a great effect of the correction can be obtained and the deformed nail can be prevented from occurring again. The corrector includes a band-shaped central region to be in contact with an upper surface of the nail and an insertion edge region continuously extended from at least one end of the band-shaped central region to be inserted between a lateral nail edge and a lateral nail fold, wherein when a direction of a base side of the nail is defined as an upstream and a direction of a tip side of the nail is defined as a downstream in a state that the corrector is attached to the nail, a screw impeller-shaped portion having a specific shape and dimension is formed on a portion including an end portion of an upstream side of the insertion edge region and a hook portion is formed on a downstream side of the insertion edge region in comparison to the screw impeller-shaped portion to hold the lateral nail edge of the nail or a lateral edge of a nail tip.
