To easily and simply connect a coil spring by performing composition by the coil spring and a core material ring-likely inserted to the inner cavity and screwing and connecting the end parts of the coil spring with each other by a small coil spring provided with an outer diameter almost equal to the inner diameter of the coil spring.

The small coil spring 22 is inserted to the end part 11 of the coil spring 1 of this eyelid opener. The coil of the small coil spring 22 enters a valley between the coil and the coil of the coil spring 1 like the screwing of a screw. The small coal spring 22 is helically advanced while fitting to the shape of the inner periphery of the coil spring 1 on a main body side and forming a male screw. Also, it is screwed to the pitch of a peak and the valley between the coil and the coil of the coil spring 1 on the main body side and is helically advanced. Thus, the small coil spring 22 is inserted in a state almost same as a screwing state.