A plurality of pits representing recording target information are formed on an optical disk, while a laser light having a predetermined power is irradiated onto the optical disk. When information is being recorded, a condition index representing a recording condition of the optical disk is derived with the use of an equation which is changeable in accordance with the kind of the optical disk and the operational environment of a recording apparatus. The power of the laser light irradiated onto the optical disk is adjusted so that the recording condition may be a predetermined recording condition based on the derived condition index.