PURPOSE: To obtain a built up tool maintaining high accuracy, by preparing the base material of a required quality through a required heat treatment to be electric discharge machined by a numerical control into a shape in accordance with a use and manufacturing each part.

CONSTITUTION: A tool prepares by electric discharge machining a hold part 1, top part 5, space parts 4, 6, deformed part 2, point end parts 7, 3, etc. from a base material 9 applying a required heat treatment. While the tool enables the required base material to be piled and electric discharge machined, further the base material can utilize an optional material of steel, special steel, cemented carbide system, Ti system, ceramics system, etc. with utilization unable in the past.