A method for manufacturing a battery is provided. The method includes suctioning a part of a strip-shaped separator in a plurality of holes of a winding core in a peripheral surface of the winding core; preparing a wound body by winding strip-shaped positive and negative electrodes along with the strip-shaped separator around the winding core; and preparing an electrode body by releasing the suction in the holes and pulling out the winding core from the wound body, in which the battery includes a battery container configured to accommodate the electrode body, the holes are communicated inside with the winging core having a hollow structure, and the winding core has an outside diameter of 2 mm or less.