In recent years, an IC chip for sending and receiving data has been extensively developed and such an IC chip is referred to as an RF tag, a radio frequency tag, an electronic tag, a radio frequency processor, a radio frequency memory, or the like (for example, see Reference 1: Japanese Patent Application Laid-Open No. 2004-282050 p. 11-14, FIG. 5). Most of IC chips currently in practical application use silicon substrates. Such IC chips are provided with thin thicknesses by forming elements over one surface of silicon substrates and then grinding and polishing a surface opposite to the one surface.