To provide a drop device of double gate doors, which is excellent in safety because the turning and extraction of a drop rod can be inhibited in the closing of the door.

This drop device of the double gate doors is mounted on the jamb of the other-side door of the double gate doors in which a jamb 4 of the one-side door and the jamb 5 of the other-side door face each other in the closing of the door. The drop device includes the drop rod 6, the lower end of which is vertically dropped in a hole 7 which is formed in a ground surface, and a drop receiver which is fixed inside the jamb 5 of the other-side door and in which openings 12A-12D for vertically inserting the drop rod are formed. A stopper 8, which is sandwiched between the jambs facing each other in the closing of the door, is fixed to a side surface of the drop rod via a spacing member 9; and notches (S1) and (S2), through which the spacing member can pass, are formed in the openings 12B and 12C of the drop receiver, and formed in positions to disable the passage of the spacing member when the stopper is sandwiched between the jambs, respectively.