An all-solid-state battery according to the present disclosure includes: a support that includes one surface; a plurality of unit battery cells that are arranged in a first direction that is parallel with the surface of the support, each including a first electrode portion and a second electrode portion with a solid electrolyte portion therebetween in a second direction that is perpendicular to the surface of the support; and an electrode connection portion that extends in the second direction, and connects first electrode portions and second electrode portions of different unit cells in series.