To make it possible to accurately detect a faulty tire by a simple method by comparing information on an unvulcanized tire before vulcanization to information on a finished product tire after vulcanization.

An article identification symbol 3 (article number) is displayed below the center identification line 2 of the tread part 1 of an unvulcanized tire W as molding information. On the other hand, a finished product tire after vulcanization has a projection/recess bar code 8 shown at the lower part of a side part and is judged as a normal tire Wx, if is judged that the article identification symbol 3 is found below the center identification line 20. However, the finished product tire is interpreted as an IG tire, i.e., a faulty tire, if it is judged that the projection/recess bar code 8 is found at the lower part of the side part and the article identification symbol 3 is found above the center identification line 2a.