A focus control is performed on the basis of a focus error signal
indicative of a deviation amount from a focus state in a recording layer
of a laser beam emitted for reproducing information to an optical disk
having a plurality of recording layers. Specifically, at the time of
focus-jumping a laser beam from a recording layer to another recording
layer, an acceleration pulse or a deceleration pulse as a brake signal
for making a focus jump is applied to a focus drive signal for
controlling driving of an optical pickup for emitting a laser beam. The
timing of applying each of the brake signals is variably set on the basis
of the level of a focus error signal of a recording layer as an object of
the focus jump. As a result, the focus jump can be accurately made in
accordance with variations in the level of the focus error signal caused
by variations in transmittance of light according to materials of the
recording layers.