To execute stable coating even if a drawing speed is increased by setting the radius of the hole of a die for coating a resin or the radius of the optical fiber entering the die so as to satisfy a specific relation at the time of subjecting the optical fiber formed by drawing from an optical fiber preform or the coated optical fiber to coating a liquid UV curing type resin.

The radius of the hole of the die 3 for coating the optical fiber 1 with the resin 4 or the radius Rf of the optical fiber 1 entering the die 3 is so set as to satisfy the relation of the equation V/Rf/log(Rd/Rf)<γc. In the equation, V is the drawing speed (m/sec), Rf is the radius (m) of the optical fiber 1 entering the die 3, Rd is the radius (m) of the hole of the die 3 and γc is the critical shearing rate (1/sec) of the resin. Consequently, the shearing rate of the resin 4 in the die 3 does not exceed the critical shearing rate even if the drawing speed of the optical fiber 1 is as high as ≥16 m/sec. The stable execution of the coating is ensured.