To provide a reflecting plate assembly for a fluorescent lamp, in which fixture and adjustment are easy with simple handling.

A reflecting plate assembly for a fluorescent lamp comprises a reflecting plate 2 for increasing illuminance and a fixing tool 3 for fixing the reflecting plate 2 to a tubular portion of the fluorescent lamp. The fixing tool 3 includes a first boss 12 having a head and a neck, a second boss 13 less in height than the boss 12, and a holder 11 for engaging the tubular portion of the fluorescent lamp for fixture. The reflecting plate 2 includes a first hole 22 having an inserting portion for inserting the head of the first boss 12 and a holding portion for holding the fixing tool in engagement with the neck, and a second hole 23 for receiving the second boss 13 when the first boss 12 is inserted into the first hole 22 and is moved to be engaged with the neck so as to fix the fixing tool to the reflecting plate.