An RFID tag comprising: an antenna configured to perform transmission/reception of signals with a reader/writer; and an IC chip to which the antenna is connected, characterized in that the RFID tag comprises: an insulating layer on which the antenna is formed; a plurality of connection terminals inside outer peripheral edges of the insulating layer ; and an annular antenna-forming area (R) formed on the entire periphery of the insulating layer , wherein the antenna is formed into a loop, with one of the plurality of connection terminals serving as a starting point and any one of the remaining connection terminals serving as an endpoint, so that a conductor line is turned within the antenna-forming area (R), wherein the conductor line has a cross-sectional shape in a longitudinal direction (H) being larger than a cross-sectional shape in a lateral direction (L), wherein turns of the conductor line that are adjacent to each other in a radial direction orthogonal to a turned direction of the antenna have the same line width (L), wherein the line width (L) is set within a range of 2 μm to 7 μm, wherein a spacing (S) between the turns of the conductor line that are adjacent to each other in the radial direction is set within a range of 2 μm to 7 μm, wherein the insulating layer is a package of the IC chip , wherein the antenna is provided on the package of the IC chip , wherein the IC chip is formed to have a rectangular shape, and wherein the plurality of connection terminals are provided at corners of the insulating layer and inside outer peripheral edges of the insulating layer . an antenna configured to perform transmission/reception of signals with a reader/writer; and an IC chip to which the antenna is connected, characterized in that the RFID tag comprises: an insulating layer on which the antenna is formed; a plurality of connection terminals inside outer peripheral edges of the insulating layer ; and an annular antenna-forming area (R) formed on the entire periphery of the insulating layer , an insulating layer on which the antenna is formed; a plurality of connection terminals inside outer peripheral edges of the insulating layer ; and an annular antenna-forming area (R) formed on the entire periphery of the insulating layer , wherein the antenna is formed into a loop, with one of the plurality of connection terminals serving as a starting point and any one of the remaining connection terminals serving as an endpoint, so that a conductor line is turned within the antenna-forming area (R), wherein the conductor line has a cross-sectional shape in a longitudinal direction (H) being larger than a cross-sectional shape in a lateral direction (L), wherein turns of the conductor line that are adjacent to each other in a radial direction orthogonal to a turned direction of the antenna have the same line width (L), wherein the line width (L) is set within a range of 2 μm to 7 μm, wherein a spacing (S) between the turns of the conductor line that are adjacent to each other in the radial direction is set within a range of 2 μm to 7 μm, wherein the insulating layer is a package of the IC chip , wherein the antenna is provided on the package of the IC chip , wherein the IC chip is formed to have a rectangular shape, and wherein the plurality of connection terminals are provided at corners of the insulating layer and inside outer peripheral edges of the insulating layer . <EOS>