To provide a sealing mechanism in a hanging door device excellently quiet with surely avoiding horizontal swing of a hanging door during opening/closing operation, having excellent installation work characteristics and capable of being manufactured at low costs, which sealing mechanism in the hanging door device surely retains air-tight performance in a fully closed state of the hanging door.

The hanging door device having the hanging door gradually descending along with closing motion comprises a shielding member placed in a guide groove opened in the bottom face formed in the opening/closing direction of the lower end section of the hanging door and an operating member connected with the end section on the tail end of the door of the shielding member and vertically movably placed in the end face on the opening side of the hanging door. The end section on the front side of the door of the shielding member is connected with and fixed to the hanging door vertically movably, and the lower end section of the operating member is rotatably connected with the shielding member. The upper end section of the operating member is connected with and fixed to the upper surface of the end section on the opening side of the hanging door. The guide groove is partitioned into a shielding member supporting section where the shielding member is located and a guide roller guide section for guiding a guide roller.