In order that it is realized to put 16× speed DVD-RAM in practice, a recording method coping with CAV (constant angular velocity) and a method for improving S/N ratio are provided and an optical disk device using them is provided. In order that a cutoff phenomenon of pulse in a laser driving circuit may not occur, the shortest pulse width is set at 1 Tw or more where Tw indicates a window width, and a recording pulse in which a 4T mark is recorded with a mono pulse where T indicates a detection window width and the parameter setting range are prescribed. Simultaneously, a reproduction power for 6× speed or more is set at 1.5-2.0 mW, different from a conventional value, and a setup sequence with which deterioration of data in reproducing does not occur is provided. Thereby it becomes possible to put 16× speed DVD-RAM in practice.