Provided is a dental laser treatment apparatus which also facilitates sterilization and cleaning work in laser beam treatment during and after the treatment, is mentally and physically less stressful to patients, and is moreover anticipated to provide quick and reliable therapeutic effects and allow for faster healing. The dental laser treatment apparatus is used for the treatment, for example, of periodontal disease using a laser beam and includes: an apparatus body which is provided with a laser beam generating device that generates a laser beam a laser beam irradiation device which has an optical fiber for supplying the laser beam generated by the laser beam generating device and a handpiece that is placed on a distal portion of the optical fiber and has an irradiation port for the laser beam and a cleaning solution supply unit for ejecting a sterilizing cleaning solution from a sterilizing cleaning solution supply unit which has a supply pipe provided with the handpiece at a distal portion thereof and which is disposed in the apparatus body or separately therefrom. The dental laser treatment apparatus is characterized in that the sterilizing cleaning solution is an aqueous solution that includes a hypochlorous acid and hypochlorous acid ions.Linvention porte également sur un appareil de traitement au laser dentaire qui facilite également le travail de stérilisation et de nettoyage dans un traitement par faisceau laser pendant et après le traitement, il est moins susceptible dêtre stressé de manière mentale et physique pour les patients, et il est en outre anticipé pour fournir des effets thérapeutiques rapides et fiables et permettre une cicatrisation plus rapide. Lappareil de traitement au laser dentaire est utilisé pour le traitement, par exemple, dune parodontopathie à laide dun faisceau laser et comprend: un corps dappareil qui est pourvu dun dispositif générateur de faisceau laser qui génère un faisceau laser un dispositif dirradiation par faisceau laser qu