A fuel cell stack includes a laminated body in which a plurality of electricity generation cells are laminated and is provided with a reaction gas discharge through hole which discharges a reaction gas used in an electricity generation reaction. An end plate is arranged at one end in the lamination direction of the laminated body and is provided with a reaction gas outlet which communicates with the reaction gas discharge through hole. A drainage structure has an outlet pipe coupled to the reaction gas outlet. A tip end portion of the outlet pipe on the downstream side in the reaction gas discharge flow direction opens downward. Umbrella-shaped protrusion portions are provided within the outlet pipe. These protrusion portions have a shape which tapers toward the upstream side with respect to the reaction gas discharge flow direction, dividing the continuous flow of the discharged liquid and the reaction gas.