A material includes various encrypted information such as product type information, product history information and authentication judging information by using an information presenting substance exhibiting line spectrums and associated with certain encrypted information corresponding to the line spectrums. Line spectrum of the information presenting substance is detected by irradiating electromagnetic waves to the material. Since the line spectrum is narrow in half-width and strong in light emitting intensity, the distinctiveness is high and therefore the encrypted information included in the material can be specified assuredly, enabling the simple and assured identification of the material.