To provide a method and a device for laser patterning a pattern- shaped thin film which is superior in quality and efficiency, of a thin-film solar cell or the like by solving the problem of lower resistance of a photoelectric conversion layer of a laser processing superposed part, the problem of a swollen part a the periphery of a processing part, the problem of damages to a base layer or a rear surface layer due to laser processing.

This method includes a processing by a single shot of laser pulse, having a thin and long rectangular shape, a prescribed width and length. A device for carrying out this method is provided with a laser pulse generating source 3, a plurality of oscillators 2, a homogenizer 5, an X-Y stage 6 and a control computer 7. In this method, laser beam are emitted from a plurality of laser oscillators and are introduced into the homogenizer 5 for shaping a laser emitting distribution to form rectangular shapes having prescribed widths and lengths. Then, light emission timing of laser beams is controlled according to the object to be processed placed on an X-Y stage.