A fuel cell has at least one engaging portion that protrudes from an outer edge of a cell and engages with a cell monitor so as to restrict movement of the cell monitor away from the cell. The cell has a plurality of engaging portions that are spaced apart from each other, and the engaging portions engage with one cell monitor at a plurality of positions of the cell. Separators of the cell contact at major surfaces thereof with cell monitor terminals. One cell monitor is mounted on a plurality of cells, and the terminals of the cell monitor are electrically connected to the separators of the cells.