Optical disk unit realizing improvement in recording quality and ATIP reading accuracy

An optical disk unit performing tracking control by generating a tracking error signal based on detection signals of reflected lights of a main light beam for recording and reproduction and sub light beams for tracking, the main light beam being focused into a spot centered on a center of a track of an optical disk, the sub light beams being focused into spots whose centers are offset from the center of the track in directions of a width of the track, the optical disk unit comprising:

• a first tracking error generation part generating a first tracking error component from the detection signals of the reflected light of the main light beam of a read-power time or an erase-power time;
• a second tracking error generation part generating a second tracking error component from the detection signals of the reflected lights of the sub light beams of all times of respective power levels;
• and
• a subtraction part obtaining the tracking error signal for a recording time by subtracting the second tracking error component from the first tracking error component.