Abstract: Herein provided is a support member for supporting an optical fiber coupler formed by arranging a plurality of optical glass fibers parallel to one another, then welding and drawing a part thereof wherein a long and thin reinforcing material of quartz whose external is at least partially formed into a circular shape is accommodated in a cylindrical metal case while coming the material into contact with the inner wall of the case; the optical fiber coupler is arranged along the reinforcing material; a portion of the optical fiber coupler which is not welded and drawn comes in contact with the reinforcing material and a part of the contact portion of the optical coupler is fixed to the material with an adhesive.