Cooling system

A cooling system of an embodiment includes a container, a housing, and a duct. The container includes an inflow passage extending in a first direction, an outflow passage positioned in a second direction, the outflow passage extending in the first direction, an inflow port through which cooling air from an air conditioning device flows in, and an outflow port through which the cooling air flows out. The housing includes shelf portions arranged between the inflow passage and the outflow passage, the shelf portions containing heat-generating modules. The housing includes intermediary passages extending between the inflow passage and the outflow passage across the shelf portions. The duct connects the inflow port and an outlet port of the air conditioning device. The duct includes a sloping face facing the cooling air and sloping in the second direction as the sloping face approaches the inflow port.