Patent ID: 6837077

Claim:
A method for producing a soot body comprising: reciprocating a glass rod and at least two end burners and at least one intermediate burner which are arranged to be opposed to the glass rod, parallel and relatively by a distance burner-to-burner interval while performing an operation that a turn-back position of the reciprocating movement is shifted by a predetermined width in a predetermined direction at every turn-back, and if the turn-back position is moved substantially by a distance of the burner-to-burner interval, the turn-back position is shifted in a reverse direction to be back to an initial position of the reciprocating movement, depositing glass particles synthesized by the burners on a surface of the glass rod while rotating the glass rod, wherein glass particle synthesizing conditions of the end burners are changed to have a greater deposition amount of glass particles per unit time than the at least one intermediate burners in at least a part of a movement range of the end burners.