A component of an endoscope is a flexible tube which is composed of a helical coil, a reticular tube formed of a braided thin wires and provided over the helical coil, and an outer cover provided over the reticular tube. The outer cover is formed of a resin material containing TiN.sub.xO.sub.y (where, 0.1.ltoreq.x.ltoreq.1.0, 0.ltoreq.y.ltoreq.1.9) which is a color developing agent to be colored when irradiated with laser light. The flexible tube is provided with scale formed by the colored portion. The outer surface the outer cover is black or dark color before the irradiation with laser light, but thus formed scale is white or blight color having a whiteness of 60% or more.