PURPOSE: To improve the working efficiency by arranging an auxiliary board composed of low melting point metal on the surface of work at the wire advancing side then performing simultaneous working and preventing adhesion of wire electrode material to the work.

CONSTITUTION: An auxiliary board 7 composed of low melting point metal such as zinc, aluminum, etc. is arranged on the surface of a work 1 at the wire advancing side, then wire cut electric discharge machining is performed simultaneously. The wire electrode 3 is removed of superficial oxide layer through initial electric discharge machining of auxiliary board 7 then adhered with low melting point metal. Consequently, chips of electrode material will never adhered to the work 1.