A cooling device includes a heat-radiating device and a centrifugal pump provided in a closed circulation passage for circulating refrigerant. The centrifugal pump contacts and absorbs heat from heat-generating electronic parts by heat exchange of the refrigerant therein to radiate the heat via the heat-radiating device. The centrifugal pump includes a lower casing that comes into contact with the heatgenerating electronic parts, an upper casing disposed to face the lower casing to form a pump chamber, and an impeller sandwiched between the upper casing and the lower casing. The lower casing includes a recessed conical surface facing the impeller, at least one protrusion provided in a center portion of the recessed conical surface and a contact face with which the heat-generating electronic parts come into contact formed directly below the protrusion on an opposite side of the recessed conical surface.