To provide a cooling system for a show case which is preferable to be used in a shop under a commercial environment where a supplying of electrical power is restricted.

A cooling system for a show case includes a compressor 41 for refrigerant, a condenser 45 for condensing the refrigerant, an expansion valve 21 for expanding the refrigerant and an evaporator 15 for heat exchanging the refrigerant with air in a show case 1 and evaporating it. The system comprises an engine 61 having a gas as its fuel for use in driving the compressor 41. Since the engine having a gas as its fuel is used, it is possible to eliminate a problem associated with a limitation of supplying an electrical power.