To provide a book with an IC tag featuring that the IC tag can hardly break during commodity circulation, and is free from the deterioration of a readout rate when a plurality of IC tags are read in a stack, and can be practically used from a viewpoint of cost.

A bag-like IC tag 3 encapsulated in a flat bag in a freely movable manner, is used as a constituent member of the book. Further, the position of an inlet 10 for the IC tag is variable in each book, so that a localized pressure becomes weak by the dispersion of an unevenness formed by the IC tag inlet 10. Consequently, no damage occurs to the IC tag inlet 10, even in case the books are stacked or bundled. In addition, when a plurality of the IC tag inlets 10 are read simultaneously in a book stack, the readout rate does not deteriorate because the mutual interference of the IC tag inlets 10 is mitigated. Besides, the mass-produced low-cost IC tag inlet 10 is only used and encapsulated in the bag as a constituent member, and therefore, the IC tag inlet 10 can be practically used even from a viewpoint of cost.