A fuel cell of the present invention includes a stack structure composed by stacking a plurality of solid oxide fuel cell units with current collectors. Each of the fuel cell unit includes: a cell plate which holds at least one cell and has a gas introduction hole for one of fuel gas and air in a center portion thereof; and a separator plate which has a gas introduction hole for the one of the fuel gas and the air in a center portion thereof and makes an outer peripheral edge thereof entirely bonded to an outer peripheral edge of the cell plate. The fuel cell further includes a casing which houses the stack structure, includes a gas introduction portion and a gas discharge portion, and introduces the other of the fuel gas and the air thereinto from the gas introduction portion and flows the other gas to the gas discharge portion. The fuel cell further includes a gas flow-regulating member provided in a gap between the casing and the stack structure in order to flow the other gas to the gas discharge portion through the current collectors located between the fuel cell units.