A radio frequency identification tag including a substrate, an antenna
provided at the substrate, the antenna formed by winding a conductor in a
coil pattern around, and on a plane orthogonal to, a center axis of the
substrate, the center axis extending in a direction parallel to the
thickness direction of the substrate, a radio frequency identification
chip attached to the substrate and operative to perform radio
communication with a reader/writer apparatus through the antenna, and a
package sealing the substrate and the antenna as well as the radio
frequency identification chip therein, wherein a mark for specifying the
center axis is formed on an outside surface where the package is exposed
to the outside.