To provide an easy structure of a fire block thin plate sheet of a building capable of setting to move from longitudinal and horizontal directions accordingly to the opening part of the building, furthermore, capable of holding a parallel condition of the sheet even when the sheet is moved.

A fire block thin plate sheet structure keeps a driving mechanism 6 and a reeling drum 2 worked in accordance with the driving mechanism 6 stored in a storage room mounted around an opening part 18, and a metallic thin sheet 1 rolled on the reeling drum 2 mounted in order to move up and down or left and right freely, and a guide member 16 for guiding both sides of the thin sheet 1 mounted in the longitudinal or horizontal direction of the storage room to make a guide ring 8 mounted in the storage room 19 near the inside of the guide member 16 work in accordance with the driving mechanism 6, and the guide ring 8 inserted in an insertion guide hole 12 perforated in the thin sheet 1 in order to move the thin sheet 1 under the parallel condition through the opening area.