To provide a pin structure which can be used for a pierce type earring and an earring by projecting a freely rotatable pin at a right angle from the ear contacting part and storing the same in a groove of the ear contacting part.

A pin 3 is rotated on its axis, advanced in a groove 6 to get over a projecting part 7, and fitted in a recessed part 7 to be fixed at a substantially right angle to an ear contacting part l. The pin 3 is rotated downward to go out of the groove 6, and stored with the point directed downward in the rear of the ear contacting part 1. As a pierce type earring, the pin 3 is erected at a right angle from the ear contacting part 1, and after the pin 3 is passed through a hole pierced in an earlobe, an annular part 14 surrounds the pin 3 to clasp an earlobe to fix the pin 3. As an earring, the pin 3 is rotated to go out of the groove 6, and guided to the back of the ear contacting part 1, and the point of the pin 3 is directed downward. The ear contact part 1 is brought into contact with the back of the earlobe, and a pressure member 9 is raised in such a manner as to clasp the earlobe and elastically energized to clasp the earlobe to be usable.