The herein-disclosed sealed battery includes a battery case, a terminal member (negative electrode external terminal) including an opposed surface opposed to the battery case, and an insulating member (negative side gasket) disposed between the sealing plate and the negative electrode external terminal. Then, the surface of the battery case and/or an opposed surface of the negative electrode external terminal includes a 1st rough surface area on at least a part of a portion contacting with the negative side gasket, and an arithmetic average roughness Sa of the 1st rough surface area is equal to or more than 1 μm. By doing this, it is possible to suppress a liquid leakage of an electrolyte caused by degradation of the negative side gasket.