To provide a floating body type derricking gate facility capable of forcibly making a door body to perform rise/fall operation by arbitrary operation when deposition of sediment occurs or it is necessary to carry out inspection, maintenance, or the like of the facility, without hindering automatic opening/closing operation of the door body at normal times.

In a floating body type derricking gate facility which is installed in a sluice pipe 1 in a water channel river bed part hinge system, a door body 2 performs rise/fall operation automatically in relation to variation of a river level to open and close a sluice pipe water passing cross section. A movable arm 10 capable of performing rise/fall operation in a hinge system is independently installed between the side part of the door body 2 and a side part door stop hardware part 4 in the same water channel as the door body 2. The movable arm 10 is connected to a wire rope 13 which makes the movable arm 10 perform rise/fall operation by winding and unwinding by an operation device 15. A push-up member for pushing up the door body 2 is provided in contact with the movable arm 10 for performing rise/fall operation on the side part of the door body 2.