PURPOSE: To provide a supporting structure of bus duct, extending invertically through the floor surface, which does not require the boring work to a cover plate of bus duct using a drill.

CONSTITUTION: Parallel supporting bases 55 are fixed on the floor surface 57 and a bus duct 50 extending vertically through the floor surface 57 between the supporting bases 55 is fixed to these supporting bases 55 using a holding metal 1, a coupling metal 2 and a coupling bolt 12. Here, a slot 6 of the holding metal 1 is fitted to lugs 54 in both sides of the bus duct cover, the metal 1 is rotated for almost 90 degrees to deform the lugs 54 and the contact surface 9 of the coupling metal 2 is placed in contact with the cover plate 53 of the bus duct 50. The [-shaped surface 8 is provided between both side surfaces 4 of the holding metal to position the bolt holes 5, 11 of both metals and is then tightened with nuts 13 to 16 using a coupling bolt 12 through the holding metal 1, coupling metal 2 and supporting bases 55.