To provide a partition in a clean room with simple work by installing partition columns between the intersection of ceiling frames and floors, and fitting an air-tight curtain material along the ceiling frames and the partition columns.

A ceiling frame 2 in which frames 1 are arranged in a lattice shape, is provided along the boundary on the zone to be demarcated in a clean room, and partition columns 4, 4 are installed between the lattice intersection 3 and a floor. An upper edge of air-tight curtain materials 5, 5 are fitted by members 6, 6 for fitting the upper edge constituted along the lower side of the frames 1 of the ceiling frame 2, and a side edge of the air-tight material 5 is fitted by members 7, 7 for fitting the side edge constituted along the side of the partition column 4. The fitting members 6, 7 are preferably one side member of a fastener, and sewn to the other side member of the fastener provided on the air-tight material 5. A division surrounded by the air-tight material 5 is constituted in the clean room with simple work.