PURPOSE: To shift laser beam and gas at the fixed speed and to enable the stable cutting by forming a needle base part into flat shape by a press and further forming this needle base part thinner than the thickness of the flat shaped part by the press.

CONSTITUTION: The needle base part of a preform 1 is formed into flat shape by press working. By applying the press working to the needle base part formed into the flat shape, the needle base part is formed thinner than the thickness of the other part. The laser beam emitted from a laser beam oscillator 16 irradiates the needle base part of the preform 1 from a laser beam nozzle 15 and at the same time, the gas supplied from a gas supplying device 18 is injected along the laser beam from the laser beam nozzle 15. Further, motors 11, 12 are driven and a table 14 is shifted to the x and y directions at the prescribed speed. By this method, in the needle part, the part corresponding to a hole, a thread inlet and notch part is cut and one pair of the needles with hole are formed at both side of holes.