To provide nail seals and their manufacturing method for easily applying, to human nails, three-dimensional patterns having excellent design characteristics and strength against impact.

The nail seal is formed by providing an adhesive layer on a bottom face of a three-dimensional pattern formed of unexpanded rubber having rubber elasticity and maximum thickness of 1.1 mm or greater. In a side face of the three-dimensional pattern having thickness of 1.1 mm or greater, an angle formed by the bottom face and the side face from the bottom face up to a part having the thickness of 1.1 mm is 70 degrees or greater. In the manufacturing method of the nail seal, liquid rubber is poured into a casting mold, and heated and cured so as to form the three-dimensional pattern composed of unexpanded rubber having rubber elasticity. The bottom face of the pattern is adhered to the surface of the adhesive layer overlying a peelable film.