To improve the disadvantage of the conventional movable partition wall installed in a hotel or a party place that in case of an earthquake, force in the direction of surface is applied to the partition wall, irrational force is applied to a hang bolt to cause a breakdown or an unexpected accident because the partition wall is fixed vertically to the hang bolt hung down from a sash pulley.

The movable partition wall 1 is hung down on the hang bolt 4 through a turning mechanism 6 to be rocked in the direction of surface, and a lock shaft 12 for locking and unlocking the turning mechanism 6 is vertically movably provided under the hang bolt. In the vicinity of the turning mechanism 6, a fixing device 15 pressed to hanger rail 2 for immovably fixing the movable partition wall 1 is retractably provided. A connecting shaft 16 of the fixing device 15 and the lock shaft 12 are connected to each other by a swing arm 13 to interlock each other.