NOVELTY - A fuel cell system comprises a discharge electrical energy controller for controlling the electrical energy discharged from the cell. At the time of supplying electrical energy discharged from the cell to the energy storage and the other electrical device after detection of the request for stopping power generation, the discharge electrical energy controller supplies the electrical energy to the other electrical device.    USE - For a fuel cell vehicle.    ADVANTAGE - The discharge process is carried out after the scavenging process, thus reducing the charge/discharge losses in the energy storage, and losses by the DC/DC converter. The time period from the time when the request for stopping power generation is received to the time when the cell system is stopped, is reduced. The energy efficiency is high.    DETAILED DESCRIPTION - A fuel cell system comprises:    (1) a fuel cell for power generation by reaction of reactant gases supplied to the fuel cell;    (2) an energy storage for assisting the output of the cell, and charged with electrical energy supplied from the fuel cell through direct current (DC/DC) converter;    (3) electrical device(s) other than the energy storage;    (4) a detector for detecting a request for stopping power generation of the cell; and    (5) a discharge electrical energy controller for controlling electrical energy discharged from the cell.    At the time of supplying electrical energy discharged from the cell to the energy storage and the other electrical device after detection of the request for stopping power generation, the discharge electrical energy controller supplies the electrical energy to the other electrical device only when the output voltage of the cell becomes equal to the voltage of the energy storage.    An INDEPENDENT CLAIM is also included for a method of controlling discharge electrical energy in a fuel cell system.    DESCRIPTION OF DRAWING(S) - The figure is a diagram of a fuel cell vehicle equipped with a fuel cell system.    Hydrogen supply port (20)    Hydrogen discharge port (22)    Air supply port (24)    Air discharge port (26)    Output terminal (29)