An aggregating unit for a yarn producing apparatus for producing carbon nanotube yarn from carbon nanotube fibers while allowing the carbon nanotube fibers to run, configured to aggregate the carbon nanotube fibers, the aggregating unit comprising an adjusting mechanism configured to adjust an aggregation state of the carbon nanotube fibers, wherein the aggregating unit is configured to aggregate the carbon nanotube fibers while exerting force on the carbon nanotube fibers in a direction perpendicular to a direction of the carbon nanotube fibers running, by allowing the carbon nanotube fibers to pass through a through hole in contact with the through hole, wherein the aggregating unit further comprises a plurality of assembly parts (12, 13) configured to form the through hole, wherein the adjusting mechanism is configured to adjust the aggregation state of the carbon nanotube fibers by adjusting a positional relation between the assembly parts (12, 13) and adjusting an opening area of the through hole, wherein the aggregating unit further comprises a first plate-shaped member and a second plate-shaped member as the assembly parts, the first plate-shaped member and the second plate-shaped member being provided with a first notch and a second notch respectively, the first notch and the second notch defining the through hole, wherein the adjusting mechanism is configured to adjust the opening area of the through hole by moving at least one of the first plate-shaped member and the second plate-shaped member and adjusting an overlapping state of the first notch and the second notch, wherein each of the first notch and the second notch opens to a side perpendicular to the direction of moving the at least one of the first plate-shaped member and the second plate-shaped member, and wherein the distance between the first plate-shaped member and the second plate-shaped member can be increased to permit removal of carbon nanotube fibers clogging the through hole. wherein the aggregating unit is configured to aggregate the carbon nanotube fibers while exerting force on the carbon nanotube fibers in a direction perpendicular to a direction of the carbon nanotube fibers running, by allowing the carbon nanotube fibers to pass through a through hole in contact with the through hole, wherein the aggregating unit further comprises a plurality of assembly parts (12, 13) configured to form the through hole, wherein the adjusting mechanism is configured to adjust the aggregation state of the carbon nanotube fibers by adjusting a positional relation between the assembly parts (12, 13) and adjusting an opening area of the through hole, wherein the aggregating unit further comprises a first plate-shaped member and a second plate-shaped member as the assembly parts, the first plate-shaped member and the second plate-shaped member being provided with a first notch and a second notch respectively, the first notch and the second notch defining the through hole, wherein the adjusting mechanism is configured to adjust the opening area of the through hole by moving at least one of the first plate-shaped member and the second plate-shaped member and adjusting an overlapping state of the first notch and the second notch, wherein each of the first notch and the second notch opens to a side perpendicular to the direction of moving the at least one of the first plate-shaped member and the second plate-shaped member, and wherein the distance between the first plate-shaped member and the second plate-shaped member can be increased to permit removal of carbon nanotube fibers clogging the through hole.