The cooling system includes: a frame; a plurality of electronic devices disposed in the frame and operating or functioning independently from each other; fans disposed in the frame and supplying cooling air to the electronic devices; a temperature acquiring portion for acquiring the temperature of the cooling air; an air-flow resistance adjusting portion for adjusting the air-flow resistance to the cooling air; and a controller for controlling the fans and the each air-flow resistance adjusting portion. The controller determines each target cooling air volume required for cooling each electronic device to a predetermined temperature based on temperature information acquired by the temperature acquiring portion and heat generation information on each electronic device, controls each air-flow resistance adjusting portion to set the volume of cooling air to each target cooling air volume, and performs the drive control of the fans to set the volume of cooling air to the minimum necessary.