A combustor includes an outer cylinder, a combustor liner, a plurality of main nozzles, an air flow channel part, and a plurality of water injection parts. The air flow channel part sends air introduced from an outside to between an inner peripheral surface of the outer cylinder and an outer peripheral surface of the combustor liner into the combustor liner. The plurality of water injection parts are provided on the inner peripheral surface of the outer cylinder at intervals in a circumferential direction around a central axis. The plurality of water injection parts inject water into the air flowing through the air flow channel part. The water injection part includes a first nozzle and a second nozzle. The first nozzle injects water to a first side in the circumferential direction. The second nozzle injects water to a second side in the circumferential direction.