To provide a cooling structure/method of a cabinet, which can uniformly cool inside the units even if heat generation amounts from the respective units differ, in the cooling cabinet where the plural units are mounted and convection guide boards are installed between the units.

In structure where units 2A-2D in which plural electronic circuit packages 3 are stored are piled on a cabinet 1 in a vertical direction by providing convection guide boards 4A-4D between the units. The heights of the convection guide boards 4A-4D are formed in accordance with the heat generation amounts of the units mounted below the convection guide boards. The amount of air flowing in the unit of large heat generation amount is increased and the units can uniformly be cooled with such constitution.