A cooling device includes a cooler disposed inside a shell, an inlet nozzle that is configured to feed a fluid into the shell, an outlet nozzle that is configured to feed the fluid passing through the cooler so as to flow outward, and a guide member that is configured to change a flowing direction of the fluid. The guide member has a collision surface which spreads in an inclined direction inclined with respect to the flowing direction of the fluid fed into the shell from the inlet nozzle, and which collides with the fluid, and an uneven portion formed in at least a portion of a peripheral edge portion of the collision surface.