Patent attributes
There is provided a fuel cell including a fuel cell stack having a fuel cell unit provided with, in order to enable appropriately controlling a wet state before power generation efficiency of the fuel cell is reduced, a polymer electrolyte membrane having one surface thereof provided with an oxidizer electrode and another surface thereof provided with a fuel electrode. In the fuel cell: the fuel cell unit includes plural power generation cell units and a pair of wet state detection cell units; one of the pair of wet state detection cell units includes an excessively humidified state detection cell unit which is more sensitive of an excessively humidified state than the power generation cell units; and another one of the pair of wet state detection cell units includes a dry state detection cell unit which is more sensitive of a dry state than the power generation cell units.