The fuel cell includes a fuel cell stack in which a plurality of planar power generation cells are stacked in a thickness direction thereof. The fuel cell also includes a heat exchanger provided between the two adjacent power generation cells in the stacking direction and in contact with the power generation cells, and including an internal first flow path that passes the oxidant gas or fuel gas supplied from outside. The fuel cell also includes a second flow path connected to an outlet side of the first flow path of the heat exchanger and to the cathode side or the anode side of each of the power generation cells, and supplying the oxidant gas or fuel gas that has passed through the first flow path to the cathode side or anode side of each of the power generation cells on both sides in the stacking direction of the heat exchanger.