A battery includes: a power generation element including a plurality of battery cells each having an electrode layer, a counter electrode layer, and a solid electrolyte layer located between the electrode layer and the counter electrode layer, the plurality of battery cells being laminated; a first conductive member; and a second conductive member, in which at least a portion of the plurality of battery cells are electrically connected in parallel, the parallel connection is carried out by an insulating layer and a connecting portion provided on a side surface of the power generation element, at least a portion of the plurality of battery cells are electrically connected in series, the power generation element is provided with at least one through hole that penetrates at least a portion of the plurality of battery cells in a direction of lamination and is open on at least any of a first principal surface and a second principal surface located on an opposite side to the first principal surface of the power generation element, the first conductive member is electrically connected to a first battery cell among the plurality of battery cells, passes through the at least one through hole, and extends to an opening position of the at least one through hole located on a first surface being one of the first principal surface and the second principal surface, the second conductive member is electrically connected to a second battery cell among the plurality of battery cells being different from the first battery cell, passes through the at least one through hole, and extends to an opening position of the at least one through hole located on a second surface being one of the first principal surface and the second principal surface, and the first battery cell and the second battery cell are not connected in parallel.