<p>A fan box is provided with a second air inlet at a wall surface position in upstream of a fan in addition to an air inlet in the front. An inlet/outlet portion arranged above or below the fan box has an exhaust notch arranged with the second air inlet of the fan box and an intake notch provided in the rear of the exhaust notch. The intake notch opens to the front of the device and communicates with an air duct to an unit box. The fan discharges the cooling air flowing into the first air inlet through an operating section and the cooling air flowing into the second air inlet through the inlet/outlet portion from an air outlet.</p>
