PURPOSE: To perform simple and rapid construction without needing external scaffolding and to improve workability by using a balcony slab construction device wherein form panels, a floor joist, a sleeper, and pipe supports are combined together, and a handrail is integrally formed.

CONSTITUTION: Form panels 11 for placing a balcony slab 1, a floor joist 12, a sleeper 13, and pipe supports 14 are integrally assembled together. A handrail 15 is arranged at overhang parts 11a and 12a extending externally of the panel 11 and the floor joist 12 to form a construction device 10, which is moved, arranged, and removed on a whole. The whole of the device 10 is lifted by a lifting means and arranged on the balcony slab 1 at a lower story. After the device is positioned at a given height through operation of a regulation screw 14a, concrete is placed. This constitution ensures scaffolding by the overhang part 11a and the handrail 15, saves labor required for an assembly and demolding work, and shortens a working time.