In an optical recording medium drive apparatus, an optical recording
medium is illuminated with a laser beam emitted from a head via an
objected leans, and the head detects light reflected from the optical
recording medium being illuminated with the laser beam. A signal
generator generates a reflected light signal in accordance with the
reflected light detected by the head. A controller drives the objective
lens via a focusing unit, and detects peaks in the reflected light signal
obtained when the objective lens is driven in a focusing direction. The
controller determines whether the optical recording medium is of a single
layer type or a multiple layer type by determining whether a pattern of
the detected peaks is similar to one of patterns which can occur if the
optical recording medium is of the single layer type.