A lamp includes a plurality of semiconductor light-emitting elements arrayed linearly, an aluminum substrate on which the plurality of light-emitting elements are mounted, and a linear light wavelength conversion member disposed separated from light-emitting surfaces of the plurality of light-emitting elements. The aluminum substrate includes a circuit formed such as to be able to switch on/off the plurality of light-emitting elements, as grouped into a plurality of sets, on a per-set basis in which the sets are composed of either one or a plurality of the light-emitting elements.

A lamp control device includes: an output; a comparator; and a first setter configured to set the voltage fed to a first input terminal of the comparator to a second voltage that depends on a first voltage or to a third voltage that depends on a first current, in which the output terminal is connected to a second input terminal of the comparator, the output terminal is configured to be connectable to the lamp via a switch, the output terminal is configured to be connectable to a second setter including the switch, when the first setter sets the voltage fed to the first input terminal of the comparator to the second voltage, and the second setter is configured to set the voltage fed to the output terminal to a fourth voltage that depends on the first voltage and the resistance value of the switch.