According to an aspect of the embodiment, a wireless tag which outputs information through a communication part in response to a command of a controlling part. The wireless tag has a storage part which stores a plurality of encrypted identifications. The wireless tag has an output part outputting an identification which has not been output yet, of the identification stored in said storage part, out of the identifications stored in the storage part, when a request for outputting the identification is externally transmitted, through said communication part in accordance with said controlling part. The wireless tag includes a restricting part, which restricts an output of the encrypted identification stored in said storage part in accordance with said controlling part when said output part has output all of the identification stored in said storage part.