To reduce the size by providing a heat-exchanger with a slit extending horizontally from one side end thereof, bending the lower part and the other side thereof to form a substantially recessed shape, bending the upper part of the slit in parallel from the inside of the lower part, dividing a side plate corresponding to one side of the heat-exchanger at a position facing the slit and arranging the divided side plate vertically.

A heat-exchanger 3 is provided with a slit A extending horizontally from one side end thereof, the lower part and the other side thereof are bent to form a substantially recessed or L-shaped part, the upper part of the slit is bent substantially in parallel from the inside of the lower part, and a side plate 3a corresponding to one side of the heat-exchanger 3 is divided at a position facing the slit A into an upper part 3a' and a lower part 3a and arranged vertically on one side of the heat-exchanger 3. The heat-exchanger disposed on a bottom plate while being formed in substantially recessed shape or L-shape is provided with a step on one side thereof so that the body size can be reduced. Alternatively, the diameter of a fan can be increased relatively.