FUEL CELL SYSTEM

A fuel cell system includes a fuel cell including a plurality of stacked cells, a fuel gas supply unit configured to supply fuel gas to a supply port of the fuel cell and return the fuel gas exhausted through an exhaust port of the fuel cell, and a controller configured to control an operation of the fuel gas supply unit. The controller is configured to execute a drain process for draining residual water accumulated in the fuel cell through the exhaust port. In the drain process, a first process in which the fuel gas is supplied to the fuel cell until a pressure in the fuel cell reaches a predetermined threshold pressure and a second process in which the pressure in the fuel cell is reduced after the first process are repeatedly executed.