PURPOSE: To prevent a reduction in performance in the peak of power demand by providing a first heat storing device for evaporating liquefied natural gas and cooling a cold medium to a prescribed temperature to store the cold, and a second heat storing device for evaporating the liquefied natural gas not evaporated by the above device and further cooling the cold medium to store the cold.

CONSTITUTION: In a device for cooling the combustion air to be supplied to a gas turbine 15 by use of the cold medium cooled by liquefied natural gas(LNG), it has a first heat storing device 4 for storing a cold while partially evaporating LNG, which has a first vessel 6 for cold medium having a prescribed low temperature, a first heat exchanger tube 5 and a stirrer 8. It also has a second heat storing device for sending the evaporated LNG to the turbine 15 and also storing the cold, which has a second vessel 12 for housing a cold medium having a slightly higher temperature and a second heat exchanger tube 11. The cold medium in the first vessel 6 is sent to the upper part of the second vessel through an air cooler 16, and the cold medium in the lower layer in the second vessel 12 is transferred into the first vessel to store the cold in each heat storing device.