In an optical head according to the present invention, an act base on which an objective lens is arranged is formed in a rectangular shape with through holes formed in four corners thereof. A base on which a collimating lens is arranged has projections to engage with the through holes in correspondence with the through holes when the act base is arranged. With the through holes of the act base engaged with the projections of the base, an adhesive is injected to the through holes to thereby fix the act base to the base. This improves the accuracy in bonding between the base and the act base, and permits laser light of a more stable intensity accordingly to be irradiated to the optical disc, thus permitting suppressing failure involved in data recording or reading.