PURPOSE: To provide softness and keep a spring property stably by using a large number of stranded thin wires of a copper alloy such as copper containing tin as a conductor.

CONSTITUTION: A large number of stranded thin wires are used as a conductor. A conductor 1 with outer diameter 0.51mm prepared by stranding thirty element wires with diameter 0.88mm of copper containing, for example, a prescribed % of tin is coated with an insulating coating 2 of polyvinyl chloride resin composition with 0.2mm thickness to give an insulated electric cable. Then, four of the insulated electric cables are quad-stranded, a transversely rolled shield layer 3 consisting of fifty of element wires with diameter 0.08mm is formed in the outer side to make the outer diameter be 2.4mm and further an outer coating 4 with 0.25mm thickness of polyvinyl chloride resin composition is formed to obtain a shielded cable with outer diameter 2.9mm. The shielded cable is coiled densely on a round bar with diameter 20mm, the resulting body is heated at 120°C-150°C for 30 minutes to 1 hour, cooled in air, and then the coiled cord is reversely coiled to give a curled cord with 15cm length of the curled part.