PURPOSE: To save weight and increase reinforcing property and at the same time improve pasting workability to a curved adherend surface by a structure wherein the adherent sheet concerned consists of a first thermosetting resin composition layer containing expanding agent, which decomposes and expands by heating, and short fibers and a second tacky thermosetting resin composition layer.

CONSTITUTION: The reinforcing adherent sheet concerned consists of a first thermosetting resin composition layer and a second thermosetting resin composition layer. By containing expanding agent and at the same time short fibers in the first thermosetting resin composition, the thickness of the first layer after curing by heating can be made thicker without making the thickness of the first layer under uncured state thicker, resulting in allowing to check the lowering of the strength of resin even after hardening and expanding. Accordingly, the thickness of the first layer can be made thinner, resulting in improving the flexibility of the whole adherent sheet for reinforcing thin sheet and making the pasting workability to a curved adherend surface favorable. Further, since the short fibers are added to the first thermosetting resin composition layer, the lowering of strength of the first thermosetting resin composition layer due to expanding is checked and consequently the reinforcing property can be improved. Furthermore, since the second thermosetting resin composition layer is tacky, the sheet can be easily adhered to adherent such as thin steel sheet or the like.