The short-pulse laser light 9 emitted from the short-pulse laser light source 1 is focused on and caused to irradiate an organic crystal 8 contained in a sample container 6 via a shutter 2, intensity adjusting element 3, irradiation position control mechanism 4, and focusing optical system 5. The sample container 6 is carried on a stage 7, and can be moved in three dimensions along the x axis, y axis and z axis in an x-y-z orthogonal coordinate system with the direction of the optical axis being taken as the z axis; furthermore, the sample container 6 can be rotated about the z axis. Working of the organic crystal 8 is performed by means of short-pulse laser light that is focused on and caused to irradiate the surface of the organic crystal 8. Prior to working, nitrogen is caused to jet onto the sample container 6 by a low-temperature gas jet device C that is a cooling device; consequently, the organic crystal 8 is cooled to −150° C. or below. As a result, it is possible to work the object of working in a fixed state, and to increase the working efficiency by means of the short-pulse laser light that is used.