PROBLEM TO BE SOLVED: To provide a cut-off structure which improves workability in a face-plate exterior wall using a metal siding material or the like, and is capable of ensuring a stable water-tight performance, eliminating the need of maintenance and paneling the exterior wall.SOLUTION: Rear-side edges of exterior surface materials 4, 4 at both sides which are disposed side by side horizontally are disposed on a front face of a column 10 of a building. A face-plate rear-side cut-off material 15 formed of an elastic material is provided at the side edge of a rear side of the exterior surface material 4. An accessory supporting material 17 including a lock part 17a protruding towards a vertical joint 16 between the exterior surface materials 4, 4 is mounted to the front face of the column 10. A joint cover 20 is provided which includes a joint cover body part 20a spread between the side edges of front sides of both of the exterior surface materials 4, 4 and a locked part 20b which is locked by the lock part
