To provide a fuel oil control device for a premixed low NOx combustion chamber, capable of supplying fuel to three fuel supply systems at an accurate distribution ratio.

Oil fuel is supplied from a fuel pump 6 through pressure control valves 4c, 4a, 4b and flow control valves 3c, 3a, 3b to a pilot, main A and main B systems at a preset ratio and guided to a combustion chamber 2. A control device 1 inputs detection signals from pressure gages 5c, 5a, 5b, controls the pressure control valves 4c, 4a, 4b to make pressure different constant, controls the flow control valves 3c, 3a, 3b on the basis of constant pressure different and supplies oil fuel at a preset distribution ratio. It also inputs a gas turbine rotating number signal 9, a load signal 10 and a signal from a pressure gage 7, opens a pressure relief control valve 8 when pressure different is increased at a low load, relieves part of oil fuel, reduces pressure different and performs accurate flow control.