In a method for processing brittle material, a laser light from a laser light source irradiates the brittle material and transports an irradiating position of the laser light along a predetermined line, wherein the laser light L from a plurality of laser light sources 11, 12 . . . m1, m2 . . . mn is irradiated simultaneously onto the surface of the brittle material W, and an irradiating range of the laser light, which is set to a predetermined shape, is moved over the surface of the brittle material. Furthermore, a plurality of optical wave guides 10 . . . 10 that guide the laser light from the laser light sources 11, 12 m1, m2 . . . mn to the brittle material are provided, and composite laser light L irradiates the surface of the brittle material, with these optical wave guides 10 . . . 10 bundled together.