A manufacturing method for a glass product not having a rotatively symmetric body like an optical fiber fixing member but having a fine structure as of optical fiber engagement portions, to transfer the fine structure with a high precision without creating molding burrs, includes the steps of placing a glass material in a cavity defined by a lower mold, an upper mold, and a side mold, molding the glass material in the cavity with pressure into the glass product in so controlling that the glass material has a viscosity range of 106.5 to 109.5 poises at the beginning of molding operation with pressure, that the lower mold is at a temperature in a range such that the glass material indicates the above viscosity range, and that the upper and side molds are at a temperature in a range such that a converted viscosity of the glass material at the temperature of the upper and side molds is 5 to 100 times higher than the viscosity of the glass material at the temperature of the lower mold, and decreasing the temperature of the lower mold at the same time that or after the glass product begins to be molded with pressure. To produce an optical fiber fixing member, the lower mold has a mold face for molding optical fiber engagement portions of the optical fiber fixing member; the upper mold has a mold face for molding a bottom of the optical fiber fixing member; and the side mold has a mold face for molding a side face of the optical fiber fixing member