Focus control is performed for an optical disc having at least two data layers. One data layer is located closer than the other to a beam-incident surface of the disc. Maximum levels in positive and negative sides on a characteristic curve of a focus error signal obtained from the disc are obtained for both data layers. First and second focus balance values are obtained based on the maximum levels for the data layers, respectively. It is determined whether a difference between the first and second focus balance values satisfies at least either a first requirement or a second requirement. The first requirement requires that the difference exceed a predetermined threshold value. The second requirement requires that the second focus balance value be smaller than a predetermined threshold value. A focus balance value is selected depending on a result of the determination, for focus control.