Generally, a stent may be inserted into a lumen of a human body, or into a lesion of a blood vessel in order to maintain a passageway of the lumen, or the blood vessel. The stent may be formed of a shape memory alloy such as nitinol maintaining a uniform expansion force at a temperature of the lumen. The stent may be formed in a cylindrical shape woven by wires, and the cylindrical stent may be formed of two thin long members successively woven repeatedly in order to have a good expansion force (elastic force) in a radial direction. That is, a plurality of pins are disposed on a cylindrical manufacturing frame. Distances between the pins are same as each other. The two thin, long members each having a length of several meters are woven one after the other on the pins repeatedly. The thin, long members may be a wire member. At this point, during one member is woven, the other is in a standby status.
However, during one wire member is woven, the other wire member is left twisted or waved. Therefore, the wire members may be damaged during the above-described process, thereby being reduced in their elastic force and thus deteriorating the quality of the product.