To realize specified fuel distribution to individual burners easily while facilitating remodeling of existing pilot stage by providing variable choke points in individual liquid fuel feed passages or gas feed passages.
When a fuel lance 3 is drawn out from turbine casing, a choke ring 16 provided in a projecting air supply pipe 6 can be accessed and machined freely from the outside. Consequently, outside diameter of the choke ring 16 can be decreased and turning can be carried out little by little. Fuel distribution can thereby be regulated gradually and accurately. When choking action of a choke point 20 provided at liquid fuel supply section is varied, the fuel lance 3 is drawn out from the casing and a pin 11 is removed from a pipe part 18. A pipe part 22 is now accessible freely from the inside and can be shortened by turning. The pin 11 is then inserted in order to inspect the fuel lance 3 during operation and the machining is repeated until a desired uniform fuel distribution is attained.
TEINOOMARUTEIN MARURINGU