In a cooling apparatus of an electronic equipment, a plurality each of integrated circuit devices and large-scale integrated circuit devices are mounted onto a plurality of substrates, respectively, and a cooling fan supplies cooling air from outside to each of these integrated circuit devices. A duct having a comb-tooth shape suitable for encompassing each substrate and defining flow paths along the substrates introduces the cooling air supplied by the cooling fan to each of the integrated circuit devices. The duct includes a plurality of small holes disposed at positions corresponding to the positions of the integrated circuit devices on the substrates and having open areas corresponding to the heating values of the integrated circuit devices. The small holes flow the cooling air supplied by the cooling fan as jet streams to the integrated circuit devices. This jet stream cooling improves cooling performance and can make uniform the temperature distribution of the integrated circuit devices.