Abstract: A low-pressure mercury discharge lamp with a very good color rendering and with a color point (x.sub.L, y.sub.I) on or close to the Planckian locus, includes a gastight, radiation-transmitting envelope which contains mercury and rare gas, and a luminescent layer includinga first luminescent material activated by bivalent europium and having an emission band whose maximum lies between 470 nm and 500 nm and whose half-value width is at most 90 nm,a second luminescent material activated by bivalent manganese and having at least an emission band mainly in the red region of the visible spectrum,a third luminescent material with a band emission whose maximum lies between 430 nm and 490 nm,a fourth luminescent material with emission mainly between 520 nm and 565 nm, anda fifth luminescent material with emission mainly between 590 nm and 630 nm.