PURPOSE: To prevent a wire formed by impregnating a piano wire or a glass fiber with polyester resin from being worn or damaged, by enclosing the wire in a flexible tube made of plastic, rubber or the like.

CONSTITUTION: A wire 1 such as an FRP pole or the like is formed by impregnating a bundle of piano wires or glass fibers with polyester resin so as to form a rod-like shape, having a high restorability and a high toughness. Then, this wire 1 is inserted in a flexible tube 2 made of rubber or a plastic material such as polyethylene, polypropyrene or PVC, and then the tube 2 are sealed by pressurized heat bonding with the use of ultrasonic waves. Accordingly, no damage caused by ends part of the inside wire 1 occurs, and it is possible to prevent damage caused by contact wearing during use.