An ID tag capable of communicating data wirelessly, the size of which is reduced, and where the size of an IC chip is reduced, a limited area of the chip is effectively used, current consumption is reduced, and communication distance is prevented from decreasing. The ID tag of the invention includes an IC chip having an integrated circuit, a resonance capacitor portion and a storage capacitor portion, and an antenna formed over the IC chip so as to overlap at least partially with an insulating film interposed therebetween. The antenna, the insulating film and wirings or semiconductor films forming the integrated circuit are stacked, and one or both of capacitors in the resonance capacitor portion and the storage capacitor portion are formed by this stacked structure.