The present invention provides an IC tag which has a structure comprising a first adhesive layer formed on a surface of a substrate sheet, an electronic circuit and an IC chip connecting both ends of the electronic circuit, both formed on the surface of the first adhesive layer, and a second adhesive layer covering the electronic circuit and the IC chip. The IC tag further includes a release agent layer formed at positions corresponding to the both ends of the electronic circuit and located at the interface between the substrate sheet and the first adhesive layer. When the IC tag attached to an article is peeled off, the built-in electronic circuit is surely broken.