An electric storage device is provided with an electrode assembly including a positive electrode plate and a negative electrode plate; a case for housing the electrode assembly; a positive-electrode external terminal arranged on an outer surface of the case and electrically connected to the positive electrode plate; a negative-electrode external terminal arranged on an outer surface of the case and electrically connected to the negative electrode plate; and a gas exhaust valve formed in a region of the case on the opposite side of a region where the positive-electrode external terminal and the negative-electrode external terminal are arranged.