Abstract: A direct alcohol fuel cell system including a fuel cell unit having a direct alcohol fuel cell including an anode electrode, an electrolyte membrane, and a cathode electrode in this order, a fuel supply unit for supplying alcohol fuel to the anode electrode, a detecting unit for detecting a current value I of a current flowing between the anode electrode and the cathode electrode of the direct alcohol fuel cell or an output voltage value V of the direct alcohol fuel cell, and a temperature T of the direct alcohol fuel cell, and a control unit for determining a supply quantity Q of alcohol fuel to the anode electrode based on detection results of the current value I or the output voltage value V, and the temperature T and controlling the fuel supply unit so that the supply quantity of the alcohol fuel is adjusted to the supply quantity Q.

Abstract: A fuel cell including a unit cell having an anode, an electrolyte membrane, and a cathode in this order, a liquid fuel accommodation portion composed of a space opening on an anode side and arranged on the anode side, for accommodating or allowing flow of liquid fuel, and a first moisture retention layer arranged between the unit cell and the liquid fuel accommodation portion is provided. This fuel cell may further include a second moisture retention layer arranged on the cathode. This fuel cell can be a direct alcohol fuel cell. For example, pure methanol or a methanol aqueous solution is adopted as the liquid fuel.