The present invention relates to an objective lens holding unit which allows for accurate information reading and writing. In order to make it possible for a read / write device including an objective lens with a small working distance, particularly such as a BD-compliant read / write device, to perform accurate information reading and writing, the objective lens holding unit of the present invention includes two ribs provided on a surface of a lens holder facing an optical disk, the lens holder holding an objective lens, so as to sandwich the objective lens therebetween. On the surfaces of the ribs facing the optical disk, protectors are provided so as to project toward the optical disk more than the objective lens does.