A method of manufacturing an optical fiber

A method of manufacturing an optical fiber, comprising the step of forming a core containing glass body; glass layer constituting the covering portion forming step; and a step in the glass tube is inserted into the vitreous; the glass body and the glass tube is characterized by the step of forming an integrated light manufacturing method, comprising the stretch side end portion of at least the glass tube is processed into the shape of the conical step. Further, the glass tube including the outer surface of the cleaning step, the difference between the inner diameter and the outer diameter of the glass tube in the glass body above 1.0mm, 10.0mm or less, the inner diameter of the support tube is mounted on one end of the glass tube is taken as the inner diameter of the glass tube or more, or tensile side end portion of the glass tube, at least the inner surface of a cone-shaped closed, the inner diameter and the outer diameter of the glass tube of vitreous clearance of substantially constant in the longitudinal direction is formed, a spacer provided (liner) .