A cooling apparatus for cooling a heating body such as a CPU by boiling and condensing refrigerant has a tank having a heating body mounting portion on which the CPU is mounted; a porous metallic sintered body arranged in the tank; and refrigerant contained in the tank. The tank has a pair of faced walls including a heat-receiving wall and a radiation wall. The porous metallic sintered body is arranged along the heat-receiving wall, and transports the refrigerant collected at the bottom of the tank to an adjacent portion of the heating body mounting portion by using a capillary action. Since the refrigerant is boiled at such a wide adjacent portion, a superheat degree of the heating body mounting portion can decrease. Furthermore, since the refrigerant collected at the bottom of the tank is transported to the adjacent portion by the capillary action, an area of the radiation wall soaked in the refrigerant becomes small. As a result, a condensation area for condensing the vapor refrigerant becomes large, and then the supercool degree of the radiation wall can decrease. In this way, a cooling capacity of the cooling apparatus can increase.