To prevent loosening due to vibration or the like and keep a screw from being simply removed by covering the head of the screw by installing an elastic member elastically engaged with the head of the screw to apply the turning force in the direction of fastening the screw.

A screwing device 1 is installed by an installing means using adopting elasticity of a coil spring. That is, an engagement part 1a projected to the lower side of a coiled part with about three turns is inserted in the head groove 3a of a screw 3, and by use of the top parts 1d, 1e of the coil elastically supporting the engagement part 1a, the force is applied in the direction of fastening the screw 3 against the elasticity 3 of the spring to fixing holes 2b, 2c of a screwed wiring board 2 to be biased, and locking parts 1b, 1c are respectively inserted in the holes and locked. Thus, when the screwing device 1 is installed, the fastening turning force is applied to the groove 3a of the screw 3 by elasticity of the coil spring, thus inhibiting loosening of the screw 3. Further, as the head of the screw 3 is covered with the coil spring, the screw 3 can be kept from being removed simply.