The present invention is aimed at providing a wireless identification tag which can save information with high reliability that is free from the possibility of being lost or falsified, is not broken or melt in the concrete, can expand directionality of an antenna, be distributed in a cement product to be in an appropriate condition for radio communication, and has good adhesion and affinity with cement or the like. A wireless identification tag 1 mixed in a cement product in the manufacturing procedure thereof in which cement, an aggregate, water, or the like are mixed including a protection body 2 incorporating the wireless identification tag 1 having an antenna portion which can write/read information by radio communication, wherein a concave portion 3 is provided on the surface of the protection body.