A method for producing a battery resulting from the joining with a plurality of weld nuggets therebetween of a foil layered part, at which foil exposed portions exposing an aluminum foil overlap, and a positive terminal member made of aluminum, includes: a formation step for forming at the foil layered part a foil welded part at which are formed, by welding aluminum foils together by means of ultrasonic welding, a first high-position part at at least a section of a surface to be joined, and a plurality of first low-position parts distributed at scattered points within the first high-position part; and a resistance-welding step for contacting the first high-position part to the positive terminal member, generating weld nuggets at the first low-position part by flowing an electric current, and resistance-welding the foil welded part and the positive terminal member with the weld nuggets therebetween.