To easily prevent a fastening member from falling off regardless a type of a part to be fastened.

A retaining member 1 is provided with a beltlike main body part 2 formed out of thin flexible material such as polyethylene terephthalate (PET) film, an adhesive paste part 3 sticking one end of the main body part 2, and a retention part 5 including roughly round hole 4 in which a male screw is fitted. The retention part 5 is provided on another end of the main body part 2 in an opposite side of the paste part 3. As an embodiment, the retention member 1 is made by forming the paste part 3 by sticking known double-faced tape on one end of the main body part 2 formed out of PET film and by forming the roughly round hole 4 on another end.