A contactless information medium comprising: a film base; an antenna coil disposed on a first surface of the film base, and formed in a spiral shape to perform wireless communication with an external device; an IC chip connected to the antenna coil via an IC chip mounting portion, and performing wireless communication processing via the antenna coil; a first plate electrode (15, 16) disposed on the first surface of the film base, and connected to at least one of an inner end and an outer end of the antenna coil; and a second plate electrode (17, 18) disposed on a second surface of the film base so as to be opposite to the first plate electrode in a thickness direction of the film base, wherein each of the first plate electrode and the second plate electrode has a first electrode portion (15a, 16a, 17a, 18a) and a second electrode portion each (15b, 16b, 17b, 18b) extending along a first side direction of the antenna coil and a second side direction intersecting the first side direction so as to be adjacent to an inner periphery or an outer periphery of the antenna coil when viewed perpendicular to the film base, or is disposed along greater than or equal to one-third of the entire length of the inner periphery or the outer periphery of the antenna coil so as to be adjacent to the inner periphery or the outer periphery of the antenna coil when viewed perpendicular to the film base, wherein the first plate electrode has a first inner plate electrode connected to the inner end of the antenna coil, and a first outer plate electrode connected to the outer end of the antenna coil, the second plate electrode has a second inner plate electrode opposite to the first inner plate electrode in the thickness direction of the film base, and a second outer plate electrode opposite to the first outer plate electrode in the thickness direction of the film base, and the first outer plate electrode is disposed on the opposite side of the first inner plate electrode with respect to a center point or center line on a plane of the film base, characterized in that the IC chip is disposed on the first surface of the film base, and the contactless information medium further comprises a jumper portion connecting the second inner plate electrode and second outer plate electrode on the second surface of the film base. a film base; an antenna coil disposed on a first surface of the film base, and formed in a spiral shape to perform wireless communication with an external device; an IC chip connected to the antenna coil via an IC chip mounting portion, and performing wireless communication processing via the antenna coil; a first plate electrode (15, 16) disposed on the first surface of the film base, and connected to at least one of an inner end and an outer end of the antenna coil; and a second plate electrode (17, 18) disposed on a second surface of the film base so as to be opposite to the first plate electrode in a thickness direction of the film base, wherein each of the first plate electrode and the second plate electrode has a first electrode portion (15a, 16a, 17a, 18a) and a second electrode portion each (15b, 16b, 17b, 18b) extending along a first side direction of the antenna coil and a second side direction intersecting the first side direction so as to be adjacent to an inner periphery or an outer periphery of the antenna coil when viewed perpendicular to the film base, or is disposed along greater than or equal to one-third of the entire length of the inner periphery or the outer periphery of the antenna coil so as to be adjacent to the inner periphery or the outer periphery of the antenna coil when viewed perpendicular to the film base, wherein the first plate electrode has a first inner plate electrode connected to the inner end of the antenna coil, and a first outer plate electrode connected to the outer end of the antenna coil, the second plate electrode has a second inner plate electrode opposite to the first inner plate electrode in the thickness direction of the film base, and a second outer plate electrode opposite to the first outer plate electrode in the thickness direction of the film base, and the first outer plate electrode is disposed on the opposite side of the first inner plate electrode with respect to a center point or center line on a plane of the film base, characterized in that the IC chip is disposed on the first surface of the film base, and the contactless information medium further comprises a jumper portion connecting the second inner plate electrode and second outer plate electrode on the second surface of the film base.