COOLING SYSTEM OF FUEL CELL

In a cooling system of a fuel cell, a first container for receiving a part of a coolant from a circulation flow path for circulating a coolant between a fuel cell and a heat exchanger is connected to the circulation flow path, a second container is connected to the first container via a pressure regulating valve, and a gas diffusion portion is provided in the second container. When a pressure inside the first container is equal to or higher than a threshold, the pressure regulating valve is opened and a gas inside the first container is released into the second container. The gas diffusion portion gradually discharges the gas released into the second container to outside of the system.