A thrust bearing structure configured to bear a thrust load in an axial direction acting on a rotor shaft, comprising: a thrust collar fixed to the rotatable rotor shaft; and a thrust bearing (43, 45) facing the thrust collar, wherein the thrust collar includes a collar pad (67, 69) on a surface thereof facing the thrust bearing, the thrust bearing (43, 45) includes a bearing pad (71, 87) on a surface thereof facing the thrust collar at a position corresponding to the collar pad (67, 69), one pad of the collar pad (67, 69) and the bearing pad (71, 87) includes a tapered section (93, 97, 73, 89), and a land section (95, 99, 75, 91) formed continuously with the tapered section (93, 97, 73, 89) at an outer edge of the tapered section (93, 97, 73, 89), the other pad of the collar pad (67, 69) and the bearing pad (71, 87) includes a flat surface which is orthogonal to a shaft center of the rotor shaft, the land section (95, 99, 75, 91) has a flat surface which is orthogonal to a shaft center of the rotor shaft and extends in a circumferential direction, the tapered section (93, 97, 73, 89) of the one pad includes a sloping surface formed to get closer to the other pad as the sloping surface gets farther away from the shaft center of the rotor shaft, a wall thickness of the tapered section (93, 97, 73, 89) is constant on a circle of an arbitrary radius having the shaft center of the rotor shaft as its center, characterized in that the tapered section is provided with a through-hole having one end opened to an oil supply pocket and the other end opened in the sloping surface for supplying oil between the collar pad (67, 69) and the bearing pad (71, 87). a thrust collar fixed to the rotatable rotor shaft; and a thrust bearing (43, 45) facing the thrust collar, wherein the thrust collar includes a collar pad (67, 69) on a surface thereof facing the thrust bearing, the thrust bearing (43, 45) includes a bearing pad (71, 87) on a surface thereof facing the thrust collar at a position corresponding to the collar pad (67, 69), one pad of the collar pad (67, 69) and the bearing pad (71, 87) includes a tapered section (93, 97, 73, 89), and a land section (95, 99, 75, 91) formed continuously with the tapered section (93, 97, 73, 89) at an outer edge of the tapered section (93, 97, 73, 89), the other pad of the collar pad (67, 69) and the bearing pad (71, 87) includes a flat surface which is orthogonal to a shaft center of the rotor shaft, the land section (95, 99, 75, 91) has a flat surface which is orthogonal to a shaft center of the rotor shaft and extends in a circumferential direction, the tapered section (93, 97, 73, 89) of the one pad includes a sloping surface formed to get closer to the other pad as the sloping surface gets farther away from the shaft center of the rotor shaft, a wall thickness of the tapered section (93, 97, 73, 89) is constant on a circle of an arbitrary radius having the shaft center of the rotor shaft as its center, characterized in that the tapered section is provided with a through-hole having one end opened to an oil supply pocket and the other end opened in the sloping surface for supplying oil between the collar pad (67, 69) and the bearing pad (71, 87).