A fuel cell stack includes: a first fuel cell and a second fuel cell, each of which has a structure in which a solid oxide electrolyte layer having oxygen ion conductivity is provided between two electrode layers; and an interconnector that is provided between the first fuel cell and the second fuel cell and has a separator made of a metal material, wherein the interconnector has a first metal porous part and a first gas passage on a first face of the separator on a side of the first fuel cell, wherein the interconnector has a second metal porous part and a second gas passage on a second face of the separator on a side of the second fuel cell.