According to one embodiment, in a multilayered write once information recording medium, the light reflectance of a recording mark formed in a first recording film by irradiation with a short-wavelength laser beam is higher than a light reflectance before irradiation with the short-wavelength laser beam, the light reflectance of a recording mark formed in a second recording film by irradiation with the short-wavelength laser beam is higher or lower than a light reflectance before irradiation with the short-wavelength laser beam, and the light reflectance of a recording mark formed in a third recording film, which is arbitrarily formed, by irradiation with the short-wavelength laser beam is higher or lower than a light reflectance before irradiation with the short-wavelength laser beam.