A fuel cell (1) has a degasifying device (4) for the fuel which is passed to the cell. The cell has an ultrasound source (5) as a part of the degasifying device. The procedure for operating a fuel cell has the following steps: (a) gas found in the liquid fuel is dissolved away, (b) the liquid gas with the dissolved gas is passed to a container, (c) the passage of the liquid fuel with dissolved gas to the container takes place below the level of the liquid found in the container, (d) the fuel passed into the container is passed on from it to the fuel cell.
