To provide a cooling fluid supply apparatus capable of continuing cooling a heat load even when supply of a cooling fluid stops while the heat load is running. A cooling fluid circulation path connecting a cooling fluid supply apparatus and a heat load and a heat-dissipating fluid circulation path connecting the cooling fluid supply apparatus and a heat-dissipating fluid supply apparatus are connected with bypass pipes and disposed therebetween. When a cooling fluid is supplied from the cooling fluid supply apparatus to the heat load, the cooling fluid circulation path and heat-dissipating fluid circulation path are disconnected by closing the bypass pipes and by using the overheating prevention valves. When the supply of the cooling fluid from the cooling fluid supply apparatus to the heat load is stopped, a heat-dissipating fluid from the heat-dissipating fluid supply apparatus is supplied to the heat load by connecting the cooling fluid circulation path and heat-dissipating fluid circulation path by using the overheating prevention valves.