WIRE ELECTRODE

PROBLEM TO BE SOLVED: To provide a brass composite wire electrode capable of achieving both processing accuracy and a processing speed.SOLUTION: A wire electrode 1 comprises: a core 10; a surface layer 20; and a partition wall layer 30. The core 10 is made of brass having a weight ratio obtained by reducing a bus line to a predetermined wire diameter, where copper is 60 W% or more to 70 w% or less, and zinc is 30 w% or more to 40 w% or less. The surface layer 20 is made of rich zinc brass of a predetermined zinc concentration, where in the diffusion layer of a layer having a thickness of 5 μm or more, a zinc concentration is 45 w% to 48 w%. The surface layer 20 is formed in a manner that while an element wire obtained by plating the core wire of brass with electric zink of 5 μm to 20 μm is horizontally pulled tense and caused to linearly travel in a horizontal direction at a predetermined fixed traveling speed, a coating layer is exposed to the atmosphere of a predetermined fixed temperature until it is zinc rich brass, uniformly heated with continuous radiation, thermally diffused to be changed into a diffusion layer of only a layer substantially, and then elongated to a desired wire diameter.