The present invention provides a gas turbine capable of reducing energy consumption while suppressing a so-called cat back phenomenon. The gas turbine includes a combustor-accommodating chamber casing for accommodating therein a combustor which burns fuel and air compressed by a compressor to generate combustion gas and which injects the combustion gas to a turbine. The gas turbine also includes a first air supply passage and a second air supply passage on an upper portion of the combustor-accommodating chamber casing in the vertical direction. The first air supply passage discharges air toward the compressor in the combustor-accommodating chamber casing. The second air supply passage discharges air in a direction different from that of the first air supply passage.