In a gas turbine plant and a gas turbine power generator plant, as a device of reducing the heat transfer from the gas turbine to the compressor, for instance, an air flow path for circulating part of compressed air from the compressor toward the gas turbine is formed between the gas turbine and the compressor. With the air flow path, which is a heat transfer reducing device, the heat conducted from the gas turbine to the compressor can be reduced by cooling or interception, and accordingly the temperature on the compressor side does not rise high, making it possible to prevent the performance of the compressor from deteriorating.