A fuel cell stack (100) includes a first power generation element, a first supporting substrate (5a), a second power generation element, a second supporting substrate (5b) and a communicating member (3). The first supporting substrate (5a) includes a first substrate main portion, a first dense layer, and a first gas flow passage. The first dense layer covers the first substrate main portion. The first gas flow passage extends from a proximal end portion (501a) to a distal end portion (502a). The second supporting substrate (5b) includes a second substrate main portion, a second dense layer, and a second gas flow passage. The second dense layer covers the second substrate main portion. The second gas flow passage extends from a proximal end portion (501b) to a distal end portion (501b). The communicating member (3) extends between the distal end portion (502a) of the first supporting substrate (5a) and the distal end portion (502b) of the second supporting substrate (5b) and communicates between the first gas flow passage and the second gas flow passage.