An attachment tag includes a stretchable circuit board having stretchability, a stretchable wiring line provided on a first main surface of the stretchable circuit board and having stretchability, an identification signal generator connected to the stretchable wiring line and configured to generate an identification signal containing identification information, a transmitter configured to transmit the identification signal generated by the identification signal generator, and an adhesive layer provided on a second main surface, different from the first main surface, of the stretchable circuit board and exhibiting adhesiveness.