METHOD FOR RUNNING A FUEL CELL SYSTEM

A fuel cell system 100 includes: a reformer 1 configured to generate a hydrogen-containing gas by using a raw material; a fuel cell 6 configured to generate electric power by using the hydrogen-containing gas; an ammonia remover 5 configured to remove ammonia from the hydrogen-containing gas generated in the reformer before the hydrogen-containing gas is supplied to the fuel cell; a fluid passage configured to allow the ammonia remover to be in communication with the atmosphere; an on-off valve 8 provided on the fluid passage and configured to allow and block the communication between the ammonia remover and the atmosphere; and a controller 80 configured to open the on-off valve in at least one of a water draining process and a water loading process of the ammonia remover.