Abstract: The laser light emitted from a laser generator is cast on two prisms which have the same angle of deflection and are supported rotatably by support members so as to be rotated about the optical axis of the laser light in the opposite directions at the same speed. The laser beam scanned through the rotations of the two prisms is focussed on a work piece by a convergence lens so that the work piece is linearly scanned for laser-working. Moreover, there are provided a pair of scanning sections, each comprising such a pair of prisms as described above, the scanning sections being so arranged that the directions of scanning the laser beam by the respective sections may be perpendicular to each other. The rotational speeds of the prisms of each scanning section is so controlled as to subject the spot of the laser beam to two-dimensional scanning for laser-working a work piece.