WIRE ELECTRIC DISCHARGE MACHINE AND WIRE ELECTRIC DISCHARGE MACHINING METHOD

PROBLEM TO BE SOLVED: To provide a wire electric discharge machine and a wire electric discharge machining method capable of surely releasing a short circuit between a wire electrode and a work.SOLUTION: The wire electric discharge machine 1 performs the electric discharge machining of the work 3 by inserting the wire electrode 2 into a prepared hole 4 formed at the work 3, and includes a short circuit detector 57 for detecting a short circuit between the wire electrode 2 and the work 3, and a short circuit releasing system for releasing the short circuit by opening and separating the wire electrode 2 and the work 3 in the prepared hole 4 by vibrating the wire electrode 2 when detecting the short circuit by the short circuit detector 57 in a state of inserting the wire electrode 2 into the prepared hole 4. The short circuit releasing system has a tension reducing means 97 for reducing the tension of the wire electrode 2 when detecting the short circuit by the short circuit detector 57.