Provided is a RFID tag capable of stably carrying out communication regardless of whether the RFID tag is attached to a metallic member or a non-metallic member. A loop antenna, including a first antenna element and a second antenna element, of this RFID tag has an overlapped section, where a first end part of the first antenna element and a second end part of the second antenna element are overlapped while being insulated from each other, on a second surface side located opposite to a first surface of a base section. The electrostatic capacitance of the overlapped section is adjusted such that the difference between the imaginary number component of a first combined impedance as viewed from the first terminal and second terminal and the imaginary number component of a second combined impedance as viewed from the first terminal and second terminal becomes equal to or smaller than a predetermined difference, said first combined impedance being obtained from the inductance of the loop antenna, the electrostatic capacitance between the loop antenna and a metallic member, and the electrostatic capacitance of the overlapped section when the second surface of the base section is attached to the metallic member, and said second combined impedance being obtained from the inductance of the loop antenna and the electrostatic capacitance of the overlapped section when the second surface of the base section is attached to a non-metallic member.