To adjust the conversion efficiency of the wavelength of light by a wavelength conversion element with high accuracy.

A luminaire 100 comprises a semiconductor laser array 10, an optical wavelength conversion element 20, a reflection mirror 30, an infrared beam splitter 35, a hologram element 45, an infrared ray sensor 40, a visible light sensor 70 and a control unit 90. The control unit 90 measures a temperature of the optical wavelength conversion element 20 by a thermistor 22 and adjusts the temperature so that the temperature reaches a target temperature, and furthermore thereafter, acquires the conversion efficiency of the wavelength from an amount of the light of an infrared laser beam measured by the infrared ray sensor 40 and an amount of light of a visible laser beam measured by the visible light sensor 70, and finely adjusts the temperature of the optical wavelength conversion element 20 so that the efficiency exceeds predetermined efficiency.