PURPOSE: To obtain the titled cooling device which can be reduced in size when transported by a method wherein a cooler is installed obliquely, and a flange part is rotated at the angle of 180°.

CONSTITUTION: A cooler flange 4 and a valve flange 9 are not orthogonally intersected with the center line of the cooler, and the center line of the cooler and the perpendicular line of the flange surface are constituted in such a manner that they are shifted in the amount of angle θ in advance. Also, a cooler 20 and the flange 4 are installed, inclining at the angle θ. Accordingly, as indicated in the diagram (b), the cooler 20 is installed at right angle with a tank 3, and a normal transformer driving state is obtained. On the other hand, the cooler 20 is in the state wherein it is reversely turned at 180° when the cooling device is in transportation as shown by the diagram (b). When the cooler flange surface 4 and the flange surface 9 are joined together under the above-mentioned condition, the center line of the cooler is shifted at the angle 2θ, and the dimensions in transportation can be made smaller.