To provide a laminate battery excellent in heat dissipation property.

A laminate battery comprises: a battery body 1; an electrode tab 2; and an electrolyte 3. The battery body 1 includes a plurality of electrode plates 11 laminated with a separator 15 interposed therebetween, each of the electrode plates being obtained by forming an active material layer 12 comprising an active material on both front and rear sides of a collector 13. The electrode tab 2 is connected to an end of the collector 13. A thickness t1 of the collector 13 constituting each of the electrode plates 11 arranged at an inside of the battery body 1 in the lamination direction is thicker than a thickness t2 of the collector 13 constituting the outermost electrode plate 11 located at the outermost of the battery body 1 in the lamination direction.