Provided is a laser processing apparatus for a light guide plate capable of providing a high-quality light guide plate by maintaining a light path at a constant level. The laser processing apparatus includes a plurality of reflecting mirrors that reflect a laser mirror; and a path adjustment block transported in a direction a distance of the light path is reduced when a laser emitting unit is transported in a direction in which the distance of the light path is increased, wherein at least one of the plurality of reflecting mirrors is installed in the path adjustment block, thereby maintaining the distance of the entire light path on which the laser beam propagates at a constant level.