A laser irradiation apparatus for bonding a first substrate and a second substrate of a display device by melting a plurality of bonding members disposed between the first and second substrates to define cells when the display device is manufactured, the display device including light emitting elements disposed on a surface of the first substrate such that the bonding members respectively encompass lateral regions of the light emitting elements, the laser irradiation apparatus including a stage on which the first substrate is mounted, a laser oscillation member configured to irradiate a laser beam that melts the bonding members disposed between the first substrate and the second substrate, and a scanner configured to irradiate the laser beam incident from the laser oscillation member onto the bonding members, the scanner being configured to sequentially irradiate the laser beam on portions of the bonding members.