Device for machining a workpiece by means of laser radiation

The invention relates to a device (1) for machining a workpiece (2) by means of parallel partial beams (3, 4) of a laser radiation (5). Arranged in the beam path of each partial beam (3, 4) is a reflector (8, 9) that deflects the respective partial beam (3, 4) into a common plane (10) parallel to a focusing plane (11) - corresponding to the surface of the workpiece (2) - in the direction of mutually opposite deflection surfaces (12, 13) of a common deflection element (14). The deflection surfaces (12, 13) are in each case arranged in a manner inclined by an angle (ss = 45 DEG ) with respect to the focusing plane (11), such that the partial beams (3, 4) are focused onto the workpiece (2) in parallel fashion.; In order to enable the distance (A1, A2) between the parallel partial beams (3, 4) on the workpiece (2) without any change in the focusing plane (11), an assigned focusing optical unit (15, 16) in the beam path of each partial beam (3, 4) is arranged such that it can be moved vertically together with the