To obtain cup wire for brassiere which can allow the brassier cups to closely contact with breast without formation of a gap or space be tween the cup and breast.

A plate material for spring is punched to form the cup wires. The cup wire is formed in a horse shoe shape in its free state so that the virtual extension wires from the curved ends P, P cross each other outside the opening 3. When it is fitted to the brassiere, the wire 1 is arranged so that it passes from the inner edge of the cup through the bottom edge and the outer edge to the half way of the top edge and the whole part is shrunk in its diameter by the elastic deformation.