In a polymer electrolyte fuel cell wherein a plurality of unit cells are arranged in a flat manner oriented in the same direction, and the prescribed adjacent unit cells are electrically connected in series so as to connect the plurality of unit cells in series, a flat-type polymer electrolyte fuel cell is made possible by providing at least one of a through hole connecting portion, a filled via connecting portion and a bump connecting portion in an insulating portion located between the prescribed adjacent unit cells, electrically insulated from the unit cells and having a thickness approximately equal to that of the unit cell, for establishing electrical connection between the prescribed adjacent unit cells.