To provide an electronic data storage medium improving the safety against leakage and theft of information.

This electronic data storage medium 11 is formed by connecting a member 17 or 17' having information showing the uniqueness expressed by the material itself thereto. The member 17 or 17' is connected to the storage medium 11 by sticking, adhesion, or paste, or by being incorporated as a part of the storage medium 11. The uniqueness expressed by the material itself is specified to, at least, one of, for example, permeability, reflectivity, absorbency, fluorescence, phosphorescence, refractive index, circular dichroism, and image information. The information showing the uniqueness expressed by the material itself is stored in a record portion 15 provided in the storage medium 11 so that the originality of the storage medium 11 can be specified by comparing it with the information obtained in collation of the storage medium.