To provide a piping structure requiring no heightening of a story height, obviating work in another dwelling unit for maintenance of piping and being excellent in maintainability.

A vertical piping space 3 penetrating through respective story parts is arranged along plural dwelling units 2 mutually juxtaposed on the upper and lower stories in a common use part 30 of a building frame 1. A floor slab 4 of the respective dwelling units 2 is provided with a pit forming part 6 having an upper surface becoming a groove-like piping pit 5 by overhanging in a beam shape to an under surface of this floor slab 4. The pit forming part 6 is arranged so as to extend to the vertical piping space 3 from the vicinity of an installing part 31 of sanitary equipment 7 to 11. Horizontally laying piping 15b and 16b becoming a drain pipe and a waste water pipe among equipment piping 15 and 16 are housed in the piping pit 5. A surface cover 18 similar to a floor material is arranged in the piping pit 5.