According to one embodiment, a cooling device includes: a heat transfer unit including a passage, through which a coolant circulates; a heat-receiving section thermally connected to a heating element; and a heat-sinking section for dissipating heat received by the heat-receiving section. The heat transfer unit includes: a first plate member, in which a groove corresponding to the passage is formed; and a second plate member, which covers the groove. The heat-receiving section is formed on one of the first and second plate members.