To record data by optimal recording power in any recording position of an inner and outer peripheries.

In an optical disk 1, PCA's which are trial writing areas for adjusting the recording power of a laser beam are disposed in both of inner and outer peripheral sides sandwiching a program area. Since the PCA's are disposed in both of the inner and outer peripheral sides, when data is recorded, one PCA near a data recording position is selected to carry out trial writing.