To provide a tag device capable of realizing a reliable lock condition and being easily unlocked, with respect to the tag device wherein a basic end part 21 of a wire 2 is fixed to a tag body 10, and a tip part 23 of the wire 2 is lockably and unlockably connected to the tag body 10.

In this tag device, the tip part 23 of the wire 2 is provided with a lock pin 22, and the lock pin 22 is provided with a thick shaft part 26 on a tip part of a thin shaft part 25. The tag body 10 is provided with a case 1 having a pin insertion hole 13, and a latch member 3 to be engaged with the lock pin 22 inserted from the pin insertion hole 13. The latch member 3 is provided with a main body reciprocatably supported inside of the case 1, and a spring piece elastically displaceably projected on the main body. In the latch member 3, the spring piece is opposite to the thin shaft part 25 of the lock pin 22 at an insertion position at one moving end to prevent the movement in the pull-out direction of the thick shaft part 26, and the spring piece 32 is separated from the thin shaft part 25 of the lock pin 22 at the insertion position at the other moving end to permit the movement in the pull-out direction of the thick shaft part 26.