To provide a mounting structure wherein a cost of manufacture is reduced, a nut can be mounted in and demounted from a plate-shaped member.

In a prescribed position of a plate-shaped part (plateshaped member) 3, oppositely to both sides in a diametric direction of a nut 5, a pair of holding tongue pieces 9 are formed by cut raising. A support tongue piece 12 into contact with the nut 5 to position it between a pair of the holding tongue pieces 9 is formed by cut raising. Dimension between a pair of the holding tongue pieces 9, in a base part 10 thereof, is formed larger than external dimension of a flange part 6 of the nut 5, in a tip end part 11 of the holding tongue piece 9, to be formed larger than two-face width dimension of a head part 7 of the nut 5, and smaller than diagonal width dimension.