To provide a cooling device for a vehicle capable of both improving cooling efficiency in an engine compartment and restraining heat damage to parts when the size of a heat exchanger is reduced.

This cooling device for a vehicle comprises a cross flow fan 12 backward in an air flow direction of a heat exchanger, and a power source 13 backward and diagonally upward in the air flow direction of the cross flow fan 12. A delivery port of the cross flow fan 12 is directed backward and diagonally upward in the air flow direction. In this cooling device for the vehicle, an engine undercover 14 of the vehicle is a diffuser structure 15 for promoting exhaust of cooling winds exhausted from the cross flow fan.