A laser irradiation device and a method of manufacturing an organic light emitting diode display device using the same. The laser radiation device prevents the scattering of the laser light into portions of the donor substrate that correspond to non-transmissive regions of a mask pattern. To reduce the scattering, the mask pattern is designed so that 1) non-transmissive regions of a surface of the mask pattern that faces the laser source have a reflective layer, 2) the surface of the mask pattern that faces the laser source is oriented to have a certain angle with respect to the laser beam axis, and 3) a surface of the mask pattern that faces the donor substrate has an anti-reflective layer. Each of these design aspects of the mask pattern prevents laser light from being scattered and prevents irradiating portions of the donor substrate that corresponds to a non-transmissive region of the mask pattern.