To provide a screw which has a fall preventing function of holding easily to an electric equipment unit by mounting a pipe-shaped holding washer whose top end is formed in a bell shape on a part of the neck of the screw, and fixing the electric equipment unit by the screw once.

A pipe-shaped hold metal fitting 4 whose top end is formed in a bell shape, is inserted matching with a spring washer 2 and a washer 3 on the neck part of a screw 1. After that, a male screw part is formed, and the screw 1 is manufactured. The screw 1 is inserted on an installing hole 8 which one part of an electric equipment unit 5 is chamfered, and it is screwed in the female screw hole 6 of a device 9 side. At this time, pressure is applied on a bell shape part by resiliency of screw fastening force, the end surface of the installing hole 8 of the unit 5 is formed as a stopper, and it is formed in a surface shape larger than the hole diameter of the installing hole such as a washer formed by a jig, the plate of the unit 5 is held between the washer 3 of the screw and it, and it becomes in a condition in which the screw 1 is not removed.