PURPOSE: To machine a material film of every sort in the precision of an (nm) order while minimizing damage.

CONSTITUTION: In a process wherein a contact hole 23 is filled up with a plug 26p to be flattened, a laminated wiring film 26b made up of a barrier metal 24b and a wiring film 25b is patterned so that a grid-shaped groove part 27g be formed, and a ductile mode cutting is applied to this groove part 27g by inserting thereinto a cutting edge 6 of diamond. It is also allowable that the groove part 27g itself is formed by the ductile mode cutting or that the cutting is started from an edge face of a material film exposed on the peripheral edge part of a wafer, without forming the groove part 27g. Since the ductile mode cutting is quite mechanical machining wherein the material film is removed through continuous plastic deformation, according to this constitution, plasma or a specific chemical liquid is unnecessary and highly precise machining can be realized at a low cost while damage is prevented.