Abstract: An electrical discharge machining apparatus is disclosed having a frame with a base and a vertical support secured to and extending upwardly from the base. A tank adapted to contain an electrolytic liquid is secured to the vertical support by an adjustment mechanism which enables the vertical position of the tank to be varied. A work holder is optionally pivotally secured to the top of the vertical support and movable between a work position in which the work support and work are aligned with the tank and an inspection position in which the work holder is laterally spaced from the tank. Electrical discharge electrodes are contained within the tank while a servo motor vertically moves the work support with its attached work against the electrodes to perform the machining operation. The electrical discharge apparatus is particularly suited for dental prosthesis applications.