PURPOSE: To enhance output and efficiency of a plant by reducing a loss.

CONSTITUTION: In a compressed air storage type power generation system using storage air, the power generating system is provided with an air storage means 1 to store compressed air, a high pressure turbine 3 driven by the compressed air from the air storage means 1, a gas turbine combustor 7 arranged downstream of the high pressure turbine 3, a low pressure turbine 4 driven by combustion gas supplied from the gas turbine combustor 7 and a cooling means which extracts a part of outlet air of the high pressure turbine 3 and supplies it to a part of a high temperature part of the low pressure turbine 4.