A gas turbine burns the air compressed in a compressor with supplying fuel in a combustor so as to obtain rotary power by supplying the generated combustion gas to a turbine. The turbine includes turbine vane elements and turbine blade elements that are alternately positioned in a direction in which the combustion gas fluidizes in a turbine cylinder having a cylindrical shape, and a flue gas diffuser having a cylindrical shape and connected to a rear portion of the turbine cylinder. The turbine blade element includes a plurality of turbine blades positioned at equal intervals in the circumference direction. The turbine blades have a throat width on a longitudinal end side made larger than a throat width on a longitudinally intermediate portion side. This efficiently restores the pressure of the flue gas. This improves the efficiency of the turbine so that the performance can be improved.