INFORMATION RECORDING MEDIUM

PURPOSE:To prevent forgery due to the rewrite of information from being performed by providing an infrared absorption bar code on an infrared reflecting layer, a thermal coloring layer absorbable an infrared ray after coloring provided on a masking layer, and identifying truth/falsehood by collating an infrared absorption waveform with magnetic recording information. CONSTITUTION:The infrared reflecting layer 11 made of milky group polyvinylchloride is provided on a plane on one side of a substrate 10, and the infrared absorption bar code 12 is provided on the layer 11. Also, the masking layer 13, the thermal coloring layer 14 containing leuco dye, and a surface protection layer 15 are provided on the layer 12. Furthermore, the magnetic recording layer 16 is provided on the plane on the other side of the substrate 10, and a back plane protection layer 17 made of a transparent polyvinylchloride is provided on the layer 16. The infrared ray projected from an infrared sensor is absorbed by a part 18 where the thermal coloring layer colors, therefore, no infrared absorption bar code is read. In such a way, since no collation with the infrared absorption bar code can be performed even when the information on the information recording layer is rewritten, thereby, the forgery can be prevented from being performed.