To provide a method of manufacturing an optical fiber, by which adhesion between a coating layer and the optical fiber is improved when a coating layer is formed on the optical fiber made of quartz glass in high-speed spinning of the optical fiber.

The temperature of a bare optical fiber 11 is raised to 60 to 110°C before it is introduced into a coating unit 4 for coating the optical fiber with a coating material. The bare optical fiber 11 is cooled by blowing a cooling gas onto it before it is introduced into a coating unit 4 for coating the optical fiber with the coating material. When the bare optical fiber 11 is cooled, at least two kinds of cooling gases having different thermal conductivities are mixed and blown onto the bare optical fiber 11. Or the temperature of the bare optical fiber 11 is controlled within a predetermined range by changing the mixing ratio of these cooling gases.