PURPOSE: To provide a technique and a device to facilitate mechanization and remarkably enhance production efficiency of a clothing button fitting process which is conventionally difficult to be mechanized and depending upon manual work among sewing work by adopting a one-touch fitted button.

CONSTITUTION: A button is constituted of a holed button 1 and a fibrous pin 5 having a sharp edge, protrusions in the middle and at an end, and a hollow hole reaching the middle of the flexible pin 5. A needle 16, provided inside of an upper part of an alligator 15, is inserted into the hollow hole of the pin 5 for guiding, and the pin 5 penetrates cloth to insert a pin tip into a button hole so as to fix the button 1 while holding an appropriate clearance between the cloth and the button 1 because of the protrusions of the pin 5. The device can be sold for personal use as a portable or an emergency set of a small hardware having a needle, and for a factory as a mechanical device of an alligator device having a needle.