A cooling device includes a device case that is arranged in an enclosure having a midplane, with a case front face facing the midplane. The device case includes a first fan unit for generating a flow of air from a side with the case front face to a side with a case rear face of the device case and a second fan unit, being stored at closer position to the side with the case front face than the first fan unit, for taking in part of air passing through one side in a width direction of the device case and flowing to the first fan unit and sending out the part of the air to the other side in the width direction of the device case. The air flow by the second fan unit can effectively cool circuitries at the rear side of the midplane.