To provide a clean room lighting system which allows easy wiring and can reduce the period of construction from the conveying of luminaires to the completion of installation.

A clean room lighting system has a horizontally elongate luminaire main body 12 having built-in lighting circuit parts 11 and at least partly stored in a storage part; a reflector 15 placed on the lower surface of the luminaire main body 12; and a fluorescent lamp 13 placed on the lower surface of the reflector 15. A power receiving connector 61 for connecting a power wire 81 thereto is placed at one longitudinal end of the luminaire main body 12. A power feeding connector 62 for bringing another power wire 81 out is placed at the other longitudinal end. Each of luminaires 10 arranged in series along a ceiling frame system is wired by using the power receiving connector 61 and the power feeder connector 62. The power feeder connector 62 of one of the adjacent luminaires 10 is connected to the power receiving connector 61 of the other luminaire 10.