To determine in a shorter time, whether the focus of a laser beam coincides with the signal recording surface of an optical disk.

In performing the focus search in an optical disk playback apparatus 1, the state of the optical disk 3 which is being currently playbacked is determined on the basis of a state determination signal S5, and either of a nearby search start position T1, which is selected in advance in accordance with the state of the optical disk 3 or a standard search start position T2 is selected. Thus, the unnecessary focus search from the nearby search start position T1 or the standard search start position T2, which is not suitable for the state of the optical disk 3, is prevented. Accordingly, the focus search can be performed in a shorter time.