PURPOSE: To provide the wire number indicator which is easily attachable and detachable and can be surely fixed to an electric wire.

CONSTITUTION: The wire number indicator body 12 is formed of an easily elastically deformable material to a U-shaped section having an opening 13 for insertion of the electric wire. Wire number characters 5 are printed on the outside surface of the indicator body 12 and one end in the longitudinal direction thereof is twisted around the longitudinal axial line relative to the other end. The indicator body 12 is twisted in the direction opposite from the initial twisting direction, by which the electric wire 3 can be inserted and removed into and from the opening 13. The indicator body 12 is restored to the initial shape by its own elasticity and is brought into tight contact with the electric wire 3 when the hand is parted therefrom in the inserted state. There is no need for tools for the adhering operation and the electric wire is not required to be cut even at the time of removing the indicator body. Since the electric wire is gripped, the generation of a positional deviation and dislodgment is obviated.