To provide an annular fluorescent lamp even adaptable even to a conventional lamp socket without needing a new lamp socket and having a base capable of suppressing tracking; and to provide a luminaire with the fluorescent lamp installed therein.

This fluorescent lamp 1 is provided with the base 6 including: a tubular base body 15 arranged so as to straddle ends 2a, 2b, 3a and 3b of an annular bulb 5 facing to each other; connection pins 14 projected to the outer surface of the tubular base body 15 and electrically connected to lead-in wires 12 wired in the inside; a recessed part 23 formed on the outer surface of the tubular base body 15 between connection pins 14 connected to the lead-in wires 12 respectively led out from a pair of ends 2a and 3a of the annular bulb 5; and a partition wall 24 projecting from the inner surface side of the tubular base body 15 corresponding to the recessed part 23 to the inside of the tubular base body 15.