To provide a burner for a boiler for preventing an ignition error and a misfire even if fuel with high volatility such as alcohol is used.

The burner includes a first nozzle 6 and a second nozzle 7. Fuel supply to the first nozzle 6 is controlled by a first fuel supply valve 12, and fuel supply to the second nozzle 7 is controlled by the second fuel supply valve 13. While fuel spray from the first nozzle 6 is continued, a combustion amount is changed in accordance with the presence/absence of fuel spray from the second nozzle 7. When fuel spray from the second nozzle 7 is started, the second fuel supply valve 13 is opened and closed once or several times in advance.