Abstract: Reference system for fixing a workpiece to a wire electric discharge machine with work table. The system consists of a base reference system attached to the work table (1) and forming a base reference surface (3) which defines a plane located on a level above the work table (1) but beneath the vertical working range of the machine and comprising two stop means (4, 5) to form the references defining the x- and y-directions of the plane. Moreover, a secondary reference system is included in the system which consists of fixed separate reference parts (10-12, 17-21) which at mounting on the base reference system, directly or as assembled outside the machine, define a fixed, desired and predetermined level within the vertical working range of the machine.