To provide a smoke barrier capable of suppressing formation of creases on an incombustible sheet, having excellent workability, and capable of thinning portions of frame edges.

A smoke barrier 10 to be mounted on a ceiling comprises an incombustible sheet 13, and members 11, 12, 14, 20 and 30 for holding four peripheral ends of the incombustible sheet respectively. At least one of the holding members is tension adjustment members 20 and 30 for adjusting tension of the incombustible sheet. The tension adjustment member includes a sheet holding member 22 to which the incombustible sheet is fitted and that can move in the width direction, a guide member 21 for guiding the moving direction of the sheet holding member, a tension adjustment screw 23 for pressing and moving the guide member, and a backing material 24 for the tension adjustment screw to which the tension adjustment screw is threadedly engaged and penetrated. A threaded engagement part between the tension adjustment screw and the backing material for the tension adjustment screw is disposed at a width-directional inner side of the sheet holding member.