A combustion burner including a fuel nozzle, a burner tube that surrounds the fuel nozzle to form an air passage between the burner tube and the fuel nozzle, swirler vanes that are arranged a circumferential direction on an external circumferential surface of the fuel nozzle, each of which extends along an axial direction of the fuel nozzle, and gradually curves from upstream to downstream so as to swirl air flowing in the air passage from the upstream to the downstream, a liquid fuel injecting hole that is formed on the fuel nozzle, and from which a liquid fuel is injected to a vane surface of each of the swirler vanes, and a cooling unit that cools a part of the vane surface on which the liquid fuel hits. The cooling unit includes a water cooling circuit formed inside the swirler vane.