Provided is a fuel cell capable of easily forming an interconnector part electrically connecting adjacent unit cells in a planar array fuel cell. In the fuel cell, an electrode layer on each of two surfaces of an electrolyte membrane is divided into a plurality of electrode regions by a dividing groove; a unit cell is constituted by a stacked structure including the electrolyte membrane, one electrode region on one surface of the electrolyte membrane, and one electrode region on the other surface thereof; and the plurality of the unit cells are connected in series by the interconnector part formed in the electrolyte membrane. The interconnector part is formed by heating and carbonizing a proton conductive resin in the electrolyte membrane. The proton conductive resin can be heated by laser beam irradiation.