To easily perform work on a heat-insulating-material arrangement plane by preventing a clip from greatly protruding from the heat-insulating-material arrangement plane, when the heat insulating material is arranged on a substrate material.

The clip 4 is split into a clip lower-part component 8 and a clip upper-part component 10. The plurality of components 8 are arranged on the substrate material 2, and fixed to the substrate material 2. The heat insulating material 12 is arranged on the substrate material 2 in such a manner as to be positioned between lower erect parts 8b of the components 8. An outer peripheral plate 14 is spread on the heat insulating material 12 in a juxtaposed manner, and a hook part 10a of the component 10 is hooked on a hook part 10a of the component 8, so that the component 10 can be detachably and slidably connected to the component 8. Side parts of the mutually outer adjacent plates 14 on the heat insulating material 12 are connected to a hanging piece part 10c of the component 10.