An information recording medium has an excellent jitter characteristic with a considerable difference in reflectance between prior to and subsequent to recording. The information recording medium includes a recording layer which contains a material having a reflectance which varies by irradiation of a light beam, on which information is recorded as reflectance variations, and a substrate for supporting the recording layer, the recording layer including a metal nitride as a major component. In a method of manufacturing the information recording medium having a recording layer which includes a material having a reflectance which varies by irradiation of a light beam, on which information is recorded as reflectance variations, and the substrate for supporting the recording layer, the recording layer including a metal nitride as a major component, the method includes a recording layer forming step for forming the recording layer by a reactive sputtering method which uses a target comprised of a metal constituting a metal nitride, wherein a flow ratio Ar:N2 in an atmosphere including Ar and N2 in the recording layer forming step is set within the range of 80:10 to 10:80.