To provide a movable suspended scaffolding apparatus which contributes to the reduction of an area necessary for suspended scaffolding, and facilitates the setting and removal thereof with respect to main girders.

A number of support beam members 14 are extended between lower flanges 4a of the main girders 4 of a bridge at necessary intervals along a longitudinal direction. Then two portions of each support beam member 14 close to both right and left ends are detachably connected to spacers 19 which extend along the main girders 4, and upper ends of vertically extending rail supports 16 are detachably connected to the two portions of each support beam member 14 close to both the right and left ends. Further a pair of right and left rails 15 located under the main girders 4 and extending along the main girders 4 are detachably connected to lower ends of the respective rail supports 16, and a scaffolding body 18 is arranged under traveling carriage devices 17 mounted to the respective rails 15 in a movable manner. Then each traveling carriage device 17 is allowed to travel along the rail 15 in a longitudinal direction, and the scaffolding body 18 is moved under the main girders 4 in the longitudinal direction.