To provide a tapered optical fiber having a good outer diameter accuracy and a high reproducibility, a manufacturing method of the tapered optical fiber, and a manufacturing system of the tapered optical fiber. The above-mentioned problem is solved by manufacturing system 1 of a tapered optical fiber comprising: shifter 11, 12 which reciprocates optical fiber 10 mounted at positions having a prescribed distance therebetween in the longer direction X of optical fiber 10 (the direction of the optical axis); and heating device 13 which heats the reciprocating optical fiber 10 at fixed position O, wherein shifter 13 includes a broadening unit which can increase the mounting distance (L1+L2) of the optical fiber while reciprocating the optical fiber. Shifter 11, 12 has at least two mounting unit which fix the optical fiber 10, and serves as a broadening unit controlling the two mounting unit independently or interlockingly. The control is performed to in order to change at least one of the ranges of reciprocal movement, the reciprocal movement speed, and the broadening width of the optical fiber fixed on the mounting unit.