A cooling device for cooling heat generating elements in which a cooling effect is produced by collision of a coolant with the back face side of heat-generating elements (1). The coolant (10) is introduced into a coolant introduction chamber (3) within a first coolant contact chamber (4) and is then introduced into the first coolant contact chamber (4) by injection from a central nozzle (7). Thereafter the coolant (10) produces a cooling effect in a second coolant contact chamber (5) and in a third coolant contact chamber (6). Since peripheral nozzles (8) and (9) are formed so as to spread in radial fashion about central nozzle (7), uniform cooling of the back face side of the heating-generating elements (1) is observed. As a result, there is no possibility of large tensile heat stress being generated at the heat-generating elements (1).