A cooling device with which thicknesses of cover portions may be reduced. According to a first aspect of the present invention, the cooling device is equipped with a frame-shaped frame portion, cover portions, a supply port, a discharge port, and projection portions. The cover portions cover openings in the frame portion. The supply port is provided in the frame portion and supplies a cooling medium into the frame portion. The discharge port is provided in the frame portion and discharges the cooling medium in the frame portion to an exterior of the frame portion. The projection portions are projected from inner side faces of the frame portion and form a fluid channel along which the cooling medium flows in the frame portion. The cover portions are fixed to the projection portions.