To provide a closure having a pull-ring wherein a finger does not hurt when tearing off a score by pulling the pull-ring with the finger, a mold for forming an inner peripheral surface of the pull-ring can be forcibly drawn out after molding, and the closure is also excellent in moldability.

The closure such as a resin cap having the pull-ring for tearing off the score has the inner peripheral surface of at least a substantial part of the pull-ring as a flat surface extending slightly slantly. An outer peripheral surface of at least a substantial part of the pull-ring is formed so that a thickness on a lower part gradually increases upwardly from a lower end, while a small protrusion connected with the lower end of the outer peripheral surface of the pull-ring is formed at a lower end of the inner peripheral surface opposite to at least a pillar of the pull-ring. The small protrusion is formed in such a shape that, when viewed in a cross section, its thickness gradually increases from its lower end toward a top and the thickness gradually decreases from the top toward an upper end.