Abstract: A cooling system is configured for arranging a cooling machine and a heat exchanger, for example, inside and outside a heat insulation box. A cooling unit for discharging cooled air by heat exchange using a refrigerant and a heat exchange unit for returning the refrigerant to a coolable condition are connected by a connection portion connecting the upper portions to form an integrated cooling device. The connection portion is arranged so as to straddle an end of a sidewall of the heat insulation box, the cooling unit is arranged inside the heat insulation box, and the heat exchange unit is arranged outside the heat insulation box. During storage or movement by a delivery vehicle, the cooling device is mounted on the heat insulation box. When carrying with hand, only the heat insulation box from which the cooling device is removed can be carried.