Abstract: Structure for and method of electrical discharge machining with a wire electrode to produce small holes including completely controlling electrical discharge machining parameters such as voltage, reactance, current and servo speed with a programmable microprocessor, central processing unit sensing first sparking between the wire electrode and the workpiece and controlling depth of cut from the position of the electrode on spark initiation electrode feeding to replenish eroded electrode through clamping sequencing between an electrical discharge machine head and an electrode carrying slide thereon. In accordance with the invention there is also provided ultrasonic vibration of at least one of the workpiece, a wire electrode guide and the electrode during machining.