To easily and accurately correct a distortion between vertical strings and lateral strings generated on the gut of a racket.

On a plate which can be fitted in the frame of a racket, protuberances of a conical, an oval conical, a triangular pyramid shape or a square pyramid shape or the like, which have the same bottom surface as a shape formed by vertical strings and lateral strings of a gut, are attached. Then, this gut distortion-correcting utensil is constituted in such a manner that by pressing the plate to the gut surface, a distortion of the gut generated by the usage of the racket is corrected by the protuberances.