To provide a tension control system in a false twist texturing machine for producing a doubled yarn wherein the target tension values or allowable ranges of hilament yarns y1 and y2 prior to doubling can be individually set for each filament yarn and wherein based on the results of the detection of the tension of the filament yarn prior to doubling, each false twister T for the corresponding filament yarn is individually and independently controlled in such a way that the tension of each filament yarn has the set target tension value or falls within the set allowable tension range. A target tension value and an allowable tension range can be individually set for eaqch filament yarn prior to doubling so as to accommodate the yarn's material, thickness, and structure, and the flase twister can be individually and independently controlled based on the results of the detection of the tension of each filament yarn prior to doubling. Consequently, higher-quality doubled false twist texturing yarns can be manufactured. IPC D01H.