PURPOSE: To provide a manufacturing method of an extruding die which can obtain a high accuracy of extrusion product as well as can be operated fully automatically.

CONSTITUTION: In this manufacturing method of extruding die, a bearing surface 4 and a tapered rearward flank 3 formed from the bearing surface 4 to the rear side are formed at the front side, and the bearing surface 4 has the depth h preset in the depth direction depending on the form of a bearing hole 1, and furthermore, the rearward flank 3 is formed by a wire cut electric discharge machining having wire electrode 20 running at a specific inclination angle to the direction vertical to the front face. Then, after the bearing surface 4 is formed by a wire cut electric discharge machining having the wire electrode 20 running in the direction vertically to the front face practically, the second rearward flank processing is carried out along the depth length h depending on the form of the bearing hole 1 by the same wire cut electric discharge machining, or after the bearing surface 4 is formed, a wire cut electric discharge machining is carried out again along the depth length h depending on the form of the bearing hole 1.