Abstract: A laser beam irradiation apparatus and method of manufacturing an organic light emitting display device using the same are disclosed. The laser beam irradiation apparatus is configured to irradiate a laser beam to an object extending in a first direction while moving the laser beam relative to the object in the first direction, where the laser beam has a cross-section taken in a plane perpendicular to a second direction in which the laser beam is irradiated from the apparatus, the cross-section comprising two substantially symmetrical portions that are substantially symmetrical about a centerline of the cross-section extending in the first direction, where the cross-section has a centerline length taken in the centerline, where at least part of the substantially symmetrical portions has a length in the first direction that is longer than the centerline length.