To provide a fuel control method and a controller for performing a fuel control in a combustion device having the combustion surfaces of a plurality of unit burners connected to increase TDR to, for instance, about 10 in which a combustion air passage is simplified and the precision of composition of previously mixed fuel gas is ensured by applying an equalizing valve system having an excellent safety to a fuel control and the generation of deviation of a flow rate of fuel to a required amount of combustion can be substantially prevented.

A novel equalizing valve which can automatically shift in multi- stages the governor characteristics of the equalizing valve correspondingly to the number of burning unit burners in accordance with the command of a controller is attached to a combustion passage. A reference position in which a diaphragm is equalized is automatically adjusted stepwise and fuel secondary pressure to combustion air pressure is maintained to a prescribed ratio by the equalizing operation.