To provide a novel power supply structure capable of eliminating or minimizing the need of changes in a power supply structure when facilities in a clean room is changed or moved.

Branch lines 32 are connected to power supply lines 31, and the branch lines are connected to a power connecting module 33 arranged in the clean room 10. The power supply lines 31 and the power connecting module 33 are normally connected by the branch lines 32 over all the power corresponding to all the power included in the power supply lines 31. The power connecting module 33 has a plurality of supply side connecting portions 33A and a plurality of output side connecting portions 33B about the power connected to the power supply lines 31 by the branch lines 32. Facility side supply lines 34 connected to a facility 20 are connected to the output side connecting portions 33B.