The utility model provides an anode container (2), which is made of metal and is used in a NaS cell. A cylindrical part (21) is provided with a straight cylindrical part (41) and a necked part (42) formed in a midway position of the straight cylindrical part (41), wherein the relationship between the wall thickness t1 of the front end (42a) of a convex part of the necked part and the wall thickness t2 of the straight cylindrical part satisfies the condition that t1 divided by t2 is greater than or equal to 1/2 or less than or equal to 1; the inner diameter of the front end (42a) of the convex part of the necked part is greater than 60 percent and less than 90 percent of the inner diameter of the straight cylindrical part; and the width h1 of the necked part (42) in the length direction of the cylindrical part is greater than 2 percent and less than 10 percent of the overall length h2 of the cylindrical part (21) . Thus the stress borne by a solid electrolyte tube (4) when the battery is warmed or cooled can be alleviated more effectively, so the stress borne by the solid electrolyte tube can be reduced even during long working time of the NaS cell, and the solid electrolyte tube can be prevented from being damaged more reliably.