INFORMATION RECORDING MEDIUM AND INFORMATION RECORDER

PROBLEM TO BE SOLVED: To use the particulates dispersed in a substrate part formed with ruggedness on the surface by the particulates incorporated into an information recording medium as a reinforcing material to enhance its rigidity by providing this information recording medium with the substrate part described above. SOLUTION: The particulates 17 are mixed with, and dispersed into the substrate part 15 of a magnetic disk 13. Thin-film parts 16 are formed on the surfaces of the substrate, i.e., the substrate part 15 including the front surfaces of the projecting particulates 17, by which the magnetic disk 13 formed with the very small ruggedness on the surfaces with the particulate 17 parts as projections is obtd. Since the particulates 17 dispersed in the substrate part 15 act as the reinforcing materials, the rigidity over the entire part is enhanced as compared with the magnetic disk formed of a pure resin. The molding of the smooth surfaces is thus facilitated and the shape change of the disk by the shrinkage at the time of the curing of the resin is lessened. Since the particulates 17 dispersed on the surfaces of the substrate part 15 are formed as the projecting parts, the formation of the uniform ruggedness is made possible.