A fuel supply device of a gas turbine engine, which supplies a fuel to a combustor including a pilot burner and a main burner; the fuel supply device comprising: a pilot fuel passage through which the fuel is supplied to the pilot burner; a main fuel passage through which the fuel is supplied to the main burner; a collecting fuel passage through which the fuel is supplied to the pilot fuel passage and to the main fuel passage; and a fuel divider which divides the fuel supplied from the collecting fuel passage to feed the fuel to the pilot fuel passage and to the main fuel passage; wherein the fuel divider includes: a fuel entrance into which the fuel supplied from the collecting fuel passage is introduced; a pilot port connected to the pilot fuel passage; a main port connected to the main fuel passage; a movable member which is movable according to a fuel pressure at the fuel entrance, the movable member being configured to open only the pilot port when the fuel pressure at the fuel entrance is lower than a first pressure, and to open both of the pilot port and the main port when the fuel pressure at the fuel entrance is higher than the first pressure; and an adjusting means for adjusting a counter force applied to the movable member which counter force acts in a direction opposite to a direction in which the movable member moves according to the fuel pressure at the fuel entrance, and wherein the value of the first pressure is adjusted by adjusting the counter force, wherein the adjusting means includes a spring element for applying the counter force to the movable member. a pilot fuel passage through which the fuel is supplied to the pilot burner; a main fuel passage through which the fuel is supplied to the main burner; a collecting fuel passage through which the fuel is supplied to the pilot fuel passage and to the main fuel passage; and a fuel divider which divides the fuel supplied from the collecting fuel passage to feed the fuel to the pilot fuel passage and to the main fuel passage; wherein the fuel divider includes: a fuel entrance into which the fuel supplied from the collecting fuel passage is introduced; a pilot port connected to the pilot fuel passage; a main port connected to the main fuel passage; a movable member which is movable according to a fuel pressure at the fuel entrance, the movable member being configured to open only the pilot port when the fuel pressure at the fuel entrance is lower than a first pressure, and to open both of the pilot port and the main port when the fuel pressure at the fuel entrance is higher than the first pressure; and an adjusting means for adjusting a counter force applied to the movable member which counter force acts in a direction opposite to a direction in which the movable member moves according to the fuel pressure at the fuel entrance, and wherein the value of the first pressure is adjusted by adjusting the counter force, wherein the adjusting means includes a spring element for applying the counter force to the movable member. a fuel entrance into which the fuel supplied from the collecting fuel passage is introduced; a pilot port connected to the pilot fuel passage; a main port connected to the main fuel passage; a movable member which is movable according to a fuel pressure at the fuel entrance, the movable member being configured to open only the pilot port when the fuel pressure at the fuel entrance is lower than a first pressure, and to open both of the pilot port and the main port when the fuel pressure at the fuel entrance is higher than the first pressure; and an adjusting means for adjusting a counter force applied to the movable member which counter force acts in a direction opposite to a direction in which the movable member moves according to the fuel pressure at the fuel entrance, and wherein the value of the first pressure is adjusted by adjusting the counter force, wherein the adjusting means includes a spring element for applying the counter force to the movable member.