PURPOSE: To cool a semiconductor device effectively utilizing the wind generated by a traveling vehicle by a method wherein the vessel, in which the cooling device is housed, is partitioned by the plate which constitutes a part of a condenser, and the wind is brought in the condenser by providing a guide plate.

CONSTITUTION: Hollow cooling pieces 5 and semiconductor elements 5 are alternately pressure welded, they are laminated in the vertical direction to the face of paper, and the vehicle proceeds in the same direction. A housing case 1 is partitioned using a plate 9, and a liquid reservoir 4, common to closed parts, and other component parts such as cooling pieces 5, the laminated material of the elements 6 and the like are housed in the closed part. The condenser 3 is placed in the section wherein the outside air can be circulated, a ventilating hole 1" is provided at the upper part of the condenser 3, and the guide plate 10 to be used to bring in the wind is installed on the outside of the air inlet port located on the side face within the limit line 11. The guide plate 10 has a trapezoidal pyramid shape, its face 10C on the top side is faced to the side of the condenser 3, fixed using the hole 10d of the frame 10b which is the extended part of the bottom face of the guide plate 10, and vanes 10C are attached to each ridge, thereby enabling to cool the condenser 3 by guiding the wind to the inlet port in either case where the vehicle makes a forward or backward movement. When the vehicle is under parking, a natural convection is utilized.