An IC tag comprising: an IC chip; a dipole antenna for electrically transmitting and receiving information stored in the IC chip; and a sheet-shaped substrate that supports the IC chip and the dipole antenna, wherein the substrate is formed in a rectangular shape and has a first side and a second side that are in a lengthwise direction of the substrate, and a third side and a fourth side that are in a widthwise direction of the substrate, wherein these sides are connected to each other in the order of the first side, the third side, the second side and the fourth side, wherein the dipole antenna includes an impedance matching portion disposed in the center of the substrate in the lengthwise direction of the substrate, and a pair of dipole portions extending from the impedance matching portion in the lengthwise direction of the substrate, wherein the impedance matching portion is formed in the shape of a rectangular frame having first to fourth sides, wherein a first side of the impedance matching portion is disposed spaced apart from the first side of the substrate, and a second side of the impedance matching portion is disposed along the second side of the substrate, and wherein the first side, a third side, the second side and a fourth side of the impedance matching portion are connected to each other in this order, wherein the IC chip is disposed in the center of the first side of the impedance matching portion, and characterized in that 0.1 ≤ R/L [Ω/cm] ≤ 2.5 is satisfied, where R is a resistance value between two ends of the dipole antenna and L is a length of a path that connects the two ends of the dipole antenna while extending along the dipole antenna without passing through the IC chip. an IC chip; a dipole antenna for electrically transmitting and receiving information stored in the IC chip; and a sheet-shaped substrate that supports the IC chip and the dipole antenna, wherein the substrate is formed in a rectangular shape and has a first side and a second side that are in a lengthwise direction of the substrate, and a third side and a fourth side that are in a widthwise direction of the substrate, wherein these sides are connected to each other in the order of the first side, the third side, the second side and the fourth side, wherein the dipole antenna includes an impedance matching portion disposed in the center of the substrate in the lengthwise direction of the substrate, and a pair of dipole portions extending from the impedance matching portion in the lengthwise direction of the substrate, wherein the impedance matching portion is formed in the shape of a rectangular frame having first to fourth sides, wherein a first side of the impedance matching portion is disposed spaced apart from the first side of the substrate, and a second side of the impedance matching portion is disposed along the second side of the substrate, and wherein the first side, a third side, the second side and a fourth side of the impedance matching portion are connected to each other in this order, wherein the IC chip is disposed in the center of the first side of the impedance matching portion, and characterized in that 0.1 ≤ R/L [Ω/cm] ≤ 2.5 is satisfied, where R is a resistance value between two ends of the dipole antenna and L is a length of a path that connects the two ends of the dipole antenna while extending along the dipole antenna without passing through the IC chip.