There is provided a method of processing an optical fiber having a core and a clad. The optical fiber has a first facet and a second facet. The method includes fixing the optical fiber in a state in which at least a portion thereof is bent in a predetermined curvature radius, applying a resist to a region on the first facet at least including an entirety of the core, irradiating the second facet with light of a predetermined wavelength so that only the resist applied to the core in the first facet is exposed to the light through an inside of the optical fiber, developing the resist, and forming a level gap at a boundary between the core and the clad in the first facet utilizing the resist remaining after the irradiating and the developing.