The RFID tag includes: a main unit consisting of a base, a communication antenna that is wired on the base, a circuit chip that is electrically connected to the antenna and performs radio communication via the antenna, a chip reinforcing member covering the periphery of the circuit chip, an underside reinforcing member that is disposed at a position that sandwiches the base with respect to the chip reinforcing member, and a rubber cover member that covers these components; and protective layers that sandwich the main unit from the front and rear sides and have greater slipperiness than the slipperiness between the main unit and a contactant.