An optical fiber manufacturing method for manufacturing an optical fiber that includes a core portion (1, 1A-1-1A-4, 1B) made of glass and a cladding portion (2, 2A, 2B) which is made of glass and which is formed on outer periphery of the core portion (1, 1A-1-1A-4, 1B), the optical fiber manufacturing method comprising: a rod setup step that includes placing, inside a glass pipe (3, 3A, 3B) constituting the cladding portion(2, 2A, 2B), a first holding member (6, 6A, 6B), which is one of a pair of holding members (5, 5A, 5B) made of glass and having a plurality of holes formed thereon, and a core rod (4, 4A-1-4, 4B-1-4, 4C), which includes a core forming portion (4a, 4Ba, 4Ca) serving as the core portion and includes a cladding forming portion (4b, 4Bb, 4Cb)serving as portion adjacent to the core portion across outer periphery of the core portion, in such a way that the core rod is supported by the first holding member; a particle filling step that includes filling glass particles in gap between inner wall face of the glass pipe and the core rod; a rod holding step that includes placing a second holding member (7, 7A, 7B) of the pair of holding members inside the glass pipe, housing the core rod and the filled glass particles in area enclosed between the inner wall face of the glass pipe, the first holding member, and the second holding member, and holding the core rod in a sandwiched manner in between the first holding member and the second holding member; a sealing step that includes sealing one end portion of the glass pipe (3, 3A, 3B) and manufacturing an intermediate object; and an optical fiber manufacturing step that includes manufacturing an optical fiber using the intermediate object, wherein a bulk density of the first holding member (6, 6A, 6B) and the second holding member (7, 7A, 7B) is set to be within a range from equal to or greater than 0.8 times to equal to or smaller than 1.2 times of a bulk density of filling portion filled with the glass particles. a rod setup step that includes placing, inside a glass pipe (3, 3A, 3B) constituting the cladding portion(2, 2A, 2B), a first holding member (6, 6A, 6B), which is one of a pair of holding members (5, 5A, 5B) made of glass and having a plurality of holes formed thereon, and a core rod (4, 4A-1-4, 4B-1-4, 4C), which includes a core forming portion (4a, 4Ba, 4Ca) serving as the core portion and includes a cladding forming portion (4b, 4Bb, 4Cb)serving as portion adjacent to the core portion across outer periphery of the core portion, in such a way that the core rod is supported by the first holding member; a particle filling step that includes filling glass particles in gap between inner wall face of the glass pipe and the core rod; a rod holding step that includes placing a second holding member (7, 7A, 7B) of the pair of holding members inside the glass pipe, housing the core rod and the filled glass particles in area enclosed between the inner wall face of the glass pipe, the first holding member, and the second holding member, and holding the core rod in a sandwiched manner in between the first holding member and the second holding member; placing a second holding member (7, 7A, 7B) of the pair of holding members inside the glass pipe, housing the core rod and the filled glass particles in area enclosed between the inner wall face of the glass pipe, the first holding member, and the second holding member, and holding the core rod in a sandwiched manner in between the first holding member and the second holding member; a sealing step that includes sealing one end portion of the glass pipe (3, 3A, 3B) and manufacturing an intermediate object; and an optical fiber manufacturing step that includes manufacturing an optical fiber using the intermediate object, wherein a bulk density of the first holding member (6, 6A, 6B) and the second holding member (7, 7A, 7B) is set to be within a range from equal to or greater than 0.8 times to equal to or smaller than 1.2 times of a bulk density of filling portion filled with the glass particles.