PURPOSE: To use plural metal-vapor discharge lamps having color rendering property different from each other as a variable color light source effectively.

CONSTITUTION: Three double-end type metal-vapor discharge lamps 2, 3, 4 having color rendering property different from each other are arranged on a rotating disc 1 with a space at 120 degree around of a rotary shaft so that fitting angles θ1, θ2, θ3 thereof relative the radial direction are different form each other. External electrodes of a metal-vapor discharge lamp 2 are connected to annular electrodes 6, 7, and external electrodes of a metal-vapor discharge lamp 3 are connected to annular electrodes 8, 9, and external electrodes of a metal-vapor discharge lamp 4 are connected to annular electrodes 10, 11.