A solid oxide fuel cell stack, comprising: cell units and separators that are alternately stacked, in which each of the cell units comprises a single cell, wherein the single cell comprises an electrolyte, an anode, and a cathode, the electrolyte is intervened between the anode and the cathode, each of the separators comprises: at least two first ridges (21,21) that are disposed on a first main surface of each of the separators at a predetermined interval to form at least one first gas channel; and at least two second ridges (22,22) that are disposed on a second main surface of each of the separators at a predetermined interval to form at least one second gas channel, the at least two first ridges and the at least two second ridges (22,22) are disposed at a regular interval from a center of each of the separators in a cross section perpendicular to the first or second gas channel, at least one first ridge of the at least two first ridges (21,21) and at least one second ridge of the at least two second ridges (22,22) of the separators are arranged such that the at least one first ridge and the at least one second ridge of a first separator of two of the separators (20,20) holding each of the cell units at least partly overlap respectively with the at least one second ridge and the at least one first ridge of a second separator of the two of the separators (20,20) in a stacking direction of the separators across a single cell intervened between the two of the separators (20,20), and each of the separators comprises: at least two first protrusions (23,23) that are disposed at a predetermined interval to form the at least one first gas channel; and at least two second protrusions (24,24) that are disposed at a predetermined interval to form the at least one second gas channel, characterized in that each of the cell units further comprises a metal support member, the metal support member comprises a center portion that includes porous metal, at least one peripheral portion including metal around the center portion, and an insulator, the anode is intervened between the electrolyte and the center portion, the insulator is disposed at a side of the cathode of the at least one peripheral portion, at least one first protrusion of the at least two first protrusions (23,23) is disposed point symmetrical to at least one second protrusion of the at least two second protrusions (24,24) with respect to the center of each of the separators in in-plane rotation and protrudes in a direction opposite to a direction of protruding the at least one second protrusion, the at least one first protrusion and the at least one second protrusion of each of the separators are arranged such that the at least one first protrusion and the at least one second protrusion of the two of the separators that hold each of the cell units overlap with each other in the stacking direction of the separators, and the at least one first protrusion and the at least one second protrusion of each of the separators are arranged such that the at least one first protrusion and the at least one second protrusion of the two of the separators (20,20) that hold each of the cell units at least partly overlap with each of the cell units but not the single cell in the stacking direction of the separators. each of the cell units further comprises a metal support member, the metal support member comprises a center portion that includes porous metal, at least one peripheral portion including metal around the center portion, and an insulator, the anode is intervened between the electrolyte and the center portion, the insulator is disposed at a side of the cathode of the at least one peripheral portion, at least one first protrusion of the at least two first protrusions (23,23) is disposed point symmetrical to at least one second protrusion of the at least two second protrusions (24,24) with respect to the center of each of the separators in in-plane rotation and protrudes in a direction opposite to a direction of protruding the at least one second protrusion, the at least one first protrusion and the at least one second protrusion of each of the separators are arranged such that the at least one first protrusion and the at least one second protrusion of the two of the separators that hold each of the cell units overlap with each other in the stacking direction of the separators, and the at least one first protrusion and the at least one second protrusion of each of the separators are arranged such that the at least one first protrusion and the at least one second protrusion of the two of the separators (20,20) that hold each of the cell units at least partly overlap with each of the cell units but not the single cell in the stacking direction of the separators.