A fuel cell that generates power when one of a fuel gas and an oxidant gas is supplied as a first reactive gas and the other is supplied as a second reactive gas, the fuel cell comprising: a cell stack in which plural single cells are collected, inner flow channels for allowing the first reactive gas to pass are formed in the single cells, the single cells cause power generation reaction when the first reactive gas is allowed to pass along a main axis direction from one end side to the other end side of the inner flow channels and the second reactive gas is brought into contact with an outer circumferential portion of the single cells; a first sidewall (71, 72) vertically provided on an outer side of the cell stack along the main axis direction, and a second sidewall (78, 79) vertically provided along the aligning direction on the outer side of the cell stack and along the main axis direction, wherein the plural single cells are vertically provided such that main axis directions of the respective single cells extend along one another and at least some of the collected single cells are arranged in a row and form linear cell groups, in the first sidewall (71, 72), first holes (713a, 723a) for supplying the second reactive gas along on aligning direction, which is a direction in which the single cells included in the linear cell groups are arranged side by side in rows, are formed such that only a part of a region projected in the aligning direction interferes with the single cells included in the linear cell groups and are formed such that a part of the second reactive gas supplied from the first holes brushes against the front single cells in the linear cell groups and, on the other hand, the remaining second reactive gas flows to the single cells in a back without brushing against the single cell, wherein the first holes (713a, 723a) are formed such that the region projected in the aligning direction does not interfere with centre lines in the main axis direction of the respective single cells included in the linear cell groups, wherein the plural single cells arranged opposed to the second sidewall (78, 79) on the outer side of the cell stack are arranged in rows and form an outer side linear cell group. second holes (714a, 724a) for supplying the second reactive gas to a region between the second sidewall (78, 79) and the outer side linear cell group are formed to have a smaller opening area than an opening area of the first holes, and wherein the second holes (714a, 724a) are formed such that the region projecting in the aligning direction does not interfere with the outer side linear cell group. a cell stack in which plural single cells are collected, inner flow channels for allowing the first reactive gas to pass are formed in the single cells, the single cells cause power generation reaction when the first reactive gas is allowed to pass along a main axis direction from one end side to the other end side of the inner flow channels and the second reactive gas is brought into contact with an outer circumferential portion of the single cells; a first sidewall (71, 72) vertically provided on an outer side of the cell stack along the main axis direction, and a second sidewall (78, 79) vertically provided along the aligning direction on the outer side of the cell stack and along the main axis direction, wherein the plural single cells are vertically provided such that main axis directions of the respective single cells extend along one another and at least some of the collected single cells are arranged in a row and form linear cell groups, in the first sidewall (71, 72), first holes (713a, 723a) for supplying the second reactive gas along on aligning direction, which is a direction in which the single cells included in the linear cell groups are arranged side by side in rows, are formed such that only a part of a region projected in the aligning direction interferes with the single cells included in the linear cell groups and are formed such that a part of the second reactive gas supplied from the first holes brushes against the front single cells in the linear cell groups and, on the other hand, the remaining second reactive gas flows to the single cells in a back without brushing against the single cell, wherein the first holes (713a, 723a) are formed such that the region projected in the aligning direction does not interfere with centre lines in the main axis direction of the respective single cells included in the linear cell groups, wherein the plural single cells arranged opposed to the second sidewall (78, 79) on the outer side of the cell stack are arranged in rows and form an outer side linear cell group. second holes (714a, 724a) for supplying the second reactive gas to a region between the second sidewall (78, 79) and the outer side linear cell group are formed to have a smaller opening area than an opening area of the first holes, and wherein the second holes (714a, 724a) are formed such that the region projecting in the aligning direction does not interfere with the outer side linear cell group.