Disclosed is a laser processing apparatus for minimizing generation of sludge and enhancing the processing efficiency while processing an object. The laser processing apparatus includes a beam irradiator for emitting a laser beam from a laser light source, a beam scanner for operating the laser beam emitted from the beam scanner, to be irradiated on a predetermined interval of a processing position of the object repeatedly on the straight, and a condensing lens for regulating a focus of the laser beam emitted from the beam irradiator. The object is movable at least once along a processing direction during processing the object. According to the present invention, it is able to improve the processing efficiency and to work an object with a uniform morphology by using a mask filtering a laser beam irradiated at a rotation turning point of a beam scanning mirror, capable of continuously irradiating a laser beam by deforming the laser beam into an elliptical pattern.