To provide a screw fall-off preventing member having simple construction reduced in the number of components for preventing the fall-off of a fixing screw from a fixed member.

The fall-off preventing member 50 comprises a mounted part 52 to be mounted to the fixed member and a fall-off preventing part 53 for preventing the fall-off of the fixing screw from the fixed member. The fall-off preventing part 53 has two fall-off preventing pieces 55 formed ranging from the opening end of an opening 54 to the inside and an initial gap 56 formed between front ends 55a of the fall-off preventing pieces 55 for permitting the passage of a screw portion of the fixing screw but prohibiting the passage of a head of the fixing screw. An after-thrust gap is formed in the passing direction of the screw portion of the fixing screw by thrusting the two fall-off preventing pieces 55. It is large enough for a middle portion of the fixing screw to be arranged therein but for the screw portion and the head portion not to pass therethrough.