PURPOSE: To indent a message consisting of a plurality of characters or patterns on the inner periphery of a ring at the store by a single effort.

CONSTITUTION: In an indenter, an indenter main body having a shaft 1, at one end of which an indenting ring 2 is detachably installed and at the other end of which an indenting grip 3 having its diameter larger than that of the indenting ring and the intermediate part of which is horizontally pivotably supported pressed with a pressing spring 4, is provided under the condition that the indenting ring has an outer diameter smaller than the inner diameter of a ring and a plurality of characters or patterns are protrusively provided on the outer periphery of the indenting ring. Further, a backing ring 8, which can hold the indenting ring and the indenting surface of the ring under the state being pressed against each other by installing the ring 7 onto the inner periphery of the indenting ring, is provided. Furthermore, the pressing spring is housed in a spring case 5, onto the outer surface of the side wall of which a moving piece 15 is fixed so as to cut the teeth of a rack at the outer periphery of the moving piece in order to provide a pinion 17 to engage with the teeth of the rack and to extend a lever from the axis of the pinion.