A radio frequency identification tag that is attached to a metal member including a slit or a groove, the radio frequency identification tag comprising: a first conductive member configured to be attached to a surface of the metal member at one side of the slit or the groove in a width direction of the slit or the groove through a first isolator, wherein a first isolator film the first isolator is laminated on the first conductive member; a second conductive member to be attached to the surface of the metal member at the other side of the slit or the groove in the width direction of the slit or the groove through a second isolator, wherein a second isolator film as the second isolator is laminated on the second conductive member; and an IC chip configured to receive power through the first conductive member and the second conductive member, characterized in that, when a frequency of radio waves that is utilized for communication is denoted by f, the power induced between the one side and the other side of the slit or the groove by receiving the radio waves is denoted by Wa, voltage induced between the one side and the other side of the slit or the groove by receiving the radio waves is denoted by V, a first area of the first conductive member is denoted by S, a second area of the second conductive member is denoted by S, a first thickness of the first isolator is denoted by d, a second thickness of the second isolator is denoted by d, a first dielectric constant of the first isolator is denoted by ε r, a second dielectric constant of the second isolator is denoted by ε r, a dielectric constant of vacuum is denoted by ε 0, and a minimum value of the power required for the IC chip to operate is denoted by Wmin, the area S of each conducive member is adjusted so that an inequality Wmin ≤ Wa - 4πf·S·ε 0 ·ε r ·V 2 /d is satisfied. a first conductive member configured to be attached to a surface of the metal member at one side of the slit or the groove in a width direction of the slit or the groove through a first isolator, wherein a first isolator film the first isolator is laminated on the first conductive member; a second conductive member to be attached to the surface of the metal member at the other side of the slit or the groove in the width direction of the slit or the groove through a second isolator, wherein a second isolator film as the second isolator is laminated on the second conductive member; and an IC chip configured to receive power through the first conductive member and the second conductive member, characterized in that, when a frequency of radio waves that is utilized for communication is denoted by f, the power induced between the one side and the other side of the slit or the groove by receiving the radio waves is denoted by Wa, voltage induced between the one side and the other side of the slit or the groove by receiving the radio waves is denoted by V, a first area of the first conductive member is denoted by S, a second area of the second conductive member is denoted by S, a first thickness of the first isolator is denoted by d, a second thickness of the second isolator is denoted by d, a first dielectric constant of the first isolator is denoted by ε r, a second dielectric constant of the second isolator is denoted by ε r, a dielectric constant of vacuum is denoted by ε 0, and a minimum value of the power required for the IC chip to operate is denoted by Wmin, the area S of each conducive member is adjusted so that an inequality Wmin ≤ Wa - 4πf·S·ε 0 ·ε r ·V 2 /d is satisfied.