Method for manufacturing soot glass deposit body

A method for manufacturing a soot glass deposit body, the method comprising a depositing step of placing a starting rod and a burner for producing glass particulates in a reaction container, introducing a source material gas to the burner through a supplying pipe, producing glass particulates by a pyrolytic oxidation reaction of the source material gas in a flame formed by the burner, and depositing the produced glass particulates on the starting rod to prepare a soot glass deposit body, wherein

• the source material gas supply pipe is disposed in the center of the burner in the longitudinal direction thereby providing a port in the center of the burner face to spout the source material gas, wherein a plurality of combustion-assisting gas ports are concentrically disposed around the source material gas port and a plurality of combustible gas ports are concentrically disposed around the combustion-assisting gas ports,
• the source material gas to be supplied to the annular burner is a siloxane,
• the burner is heated so that temperature of the burner falls within the range of from −10° C. to +30° C. relative to the boiling point of the siloxane and the supplying pipe is heated so that temperature of the supplying pipe falls within the range of from the boiling point of the siloxane to the boiling point plus 30° C., and
• wherein a heater for heating the burner is provided inside the outer casing of the burner and is disposed so as to be adjacent and substantially parallel in the longitudinal direction to the source material gas supply pipe.