Fuel cell stack

A fuel cell stack is provided with: a cell stack in which a plurality of power generation cells having electrolyte membranes are stacked in a predetermined direction; an exhaust gas flow path that is provided so as to penetrate the cell stack in a predetermined direction so as to discharge the reaction gas introduced into the plurality of power generation cells; and a flow path forming part for forming a drainage flow path for water to flow from the upstream side to the downstream side of the exhaust gas flow path. The flow path forming portion includes a communication pipe disposed in the exhaust gas flow path and provided with a first opening and a second opening respectively communicating with the upstream side and the downstream side of the exhaust gas flow path, and the flow path forming portion has a constricted portion at an inlet of the drainage flow path. 燃料电池堆具备：电池层叠体，其将具有电解质膜的多个发电电池在规定方向上层叠而成；废气流道，其在规定方向上贯通电池层叠体地设置以排出导入到所述多个发电电池的反应气体；以及流道形成部，其从废气流道的上游侧到下游侧形成供水流动的排水用流道。流道形成部包括连通管，所述连通管配置于废气流道，开设有分别与