To provide an attachment structure for attaching a solar battery or the like to a structure with a substantially flat snow-drop prevention roof; installation of the attachment structure being easy with a small number of components without damage to roof materials.

The attachment structure includes a beam folded-plate 10 having a width slightly smaller than a part except for a pair of seams 41 of lengthy steel plate roof materials 40; a crossover holding plate that is provided over foot of crest portions at both ends of the beam folded-plate 10 to close a lower portion of the beam folded-plate 10; and a round portion 26 that is formed by connecting a horizontal part 21 of the crossover holding plate to a vertical piece with an arc-shaped thin plate; and a metal fixture for haze 27 for fixing a pair of vertical pieces. The buckling strength of the crossover holding plate in the direction in which the radius of the round portion 26 increases is set to be smaller than the buckling strength of a hanger.