To facilitate positioning operation of a double-structure cable used for a vehicle with a simple structure.

In this device, a slider 14 connected with an outer casing 11 is axially movably arranged inside a cylindrical socket 13 fixed to a bracket. An inner cable 12 penetrates through the slider 14. Slider arms 21 and lock arms 22 shorter than the slider arms 21 are alternatively formed on the cylindrical socket 13, in an axially spiral manner. A fitting groove 30 is formed on the outer periphery of the slider 14, while a fitting groove 21b is formed inside the slider arm 21. A cylindrical lock ring 15 is formed so as to slide with a periphery of the slider arm 21. When a cable 4 is inserted, the slider 14 enters inside followed by adjustment of length. A plurality of slider arms 21 are reduced in diameter only by moving the lock ring 15, and fixation is performed by the fitting grooves 30, 21b.