An optical head and a disk unit are provided, in which the height and the weight of the optical head are reduced to enable a disk unit of small size and high recording density. The optical head has 2-group lenses containing a first lens arranged on a side of a semiconductor laser and a second lens arranged to face a recording layer of an optical disk, and an optical axis of the objective lens is arranged in parallel to the recording layer. The optical head can be reduced in height and the weight according to the constitution.