To solve the problem of a nozzle tip water mixing liquid burner that incomplete combustion takes place at the time of firing or transition to combustion.

The nozzle tip water mixing liquid burner comprises a gun type oil burner 2 where water is injected into fuel oil at the tip of a nozzle 1 and water mixed fuel is sprayed and burnt, a regulator 4 for regulating the quantity of water being supplied to the burner, and a regulator 5 for regulating the quantity of combustion air being supplied to the burner wherein the quantity of water being injected into fuel oil is altered by controlling the water injection controller 4. The air supply regulator 5 is controlled based on the quantity of water being injected into fuel oil thus regulating the quantity of combustion air being supplied to the burner.