A laser irradiation apparatus for bonding a first substrate to a second substrate using bonding members and a method of manufacturing a display device using the same, the laser irradiation apparatus including a stage on which the first substrate is mounted, bonding members disposed between the first substrate and the second substrate, a laser oscillating member configured to irradiate a laser beam onto the bonding members, and a temperature maintaining member co-operating with the first substrate to maintain a temperature of the first substrate at a predetermined temperature.