PURPOSE: To achieve a checking of harmful combustion frequency and a lowering of vibration pressure as generated in a premixed combustor or the like by arranging a pilot burner and a premixed gas circular burner at a certain angle to a line drawn at the right angle to a liner wall of the combustor so that the positions of the tip parts thereof are differentiated in the circumferential direction.

CONSTITUTION: Regarding a burner structure of a gas turbine combustor using a gas fuel as fuel, a pilot burner 7 is arranged at the center part thereof and a premixer 6 for premixing air with a gas fuel at the outer circumference part and in the structure of a double stage combustion burner having a burner part following the devices, outlet surfaces of the premixer 6 and the pilot burner 7 are differentiated in the circumferential direction of the burner so that a heating zone is dispersed in the longitudinal direction of a combustion base device. The maximum moving width dL of the maximum heating zone can be set freely by selecting a value angle of the burner end face 18 to a line 19 at the right angle to a wall surface of a combustor liner 3.