A gas turbine combustor having an inner tube and a transition pipe connected together is provided. The combustor includes an internal swirler and an external swirler. The internal swirler is composed of a cylindrical inward swirler ring disposed concentrically with respect to a central axis of the inner tube, and a plurality of inward swirler vanes provided on an outer peripheral surface of the inward swirler ring. The external swirler is composed of a cylindrical outward swirler ring disposed on an outer peripheral side of the inward swirler vanes and concentrically with respect to the inward swirler ring, and a plurality of outward swirler vanes provided on an outer peripheral surface of the outward swirler ring. The internal swirler and the external swirler are disposed within the inner tube.