The present invention relates to an alignment device (100) for adjusting a workpiece (400) on a machine table (300) of a numerically controlled machine tool (1000), the alignment device (100) comprises: a lower plate (20) which can be mounted on the machine table (300) of the machine tool (1000), an upper plate (10) which is movably arranged on the lower plate (20), on the upper side of which a workpiece carrier (200) can be mounted, an adjusting mechanism which is arranged between the lower plate (20) and the upper plate (10) for adjusting the relative position of the upper plate (10) to the lower plate (20), and a locking mechanism for securing the relative position of the upper plate (10) to the lower plate (20).