A locking apparatus is configured to lock a first panel and a second panel to a computer device. The locking apparatus includes a lock rotatable between a first position and a second position, a mounting panel, a driving lever pivotably attached on the mounting panel, a blocking member attached to the mounting panel, and a latch member. When moved to the first position, the rotatable post rotates the driving lever, the driving lever pushes the latch member to unlatch from the second panel, and the rotatable post is disengaged from the blocking member to unlock the first panel. When moved to the second position, the rotatable post is blocked by the blocking member for locking the first panel, the driving lever is rotated to its original position, and the latch member latches the second panel.