An optical disc apparatus includes, as a raising/lowering mechanism for
moving a second base constituting a unit mechanism portion pivotally
about a fulcrum so as to raise or lower the second base with respect to a
first base as a base of the optical disc apparatus, a cam mechanism which
is provided pivotably on the first base side within an orthographic
projection area of the optical disc that is in a chucked state and which
has a cam surface formed around and in the direction of a pivot shaft. In
addition, a cam pin provided on the second base side is brought into
engagement with the cam surface. When the optical disc inserted into the
optical disc apparatus is chucked onto a turntable so as to be rotatable,
the cam mechanism is pivoted about the pivot shaft by a cam drive
section.