A prismatic battery according to one embodiment of the present invention includes a flat electrode group 10 stacked or rolled by mutually positive and negative electrodes with a separator therebetween, a pressing plate 13A, a current collecting body 18A or 18B and a plurality of exposed sections 16, at least one end of the positive and negative electrodes substrates in a width direction being uncoated with a positive or negative electrode mixture. The pressing plate 13A is welded to the exposed sections 16. The pressing plate 13A includes opposing surfaces with a space therebetween provided by folding back a metal plate, and includes a slit 15 along a folded back section at least to one of the opposing surface's side. The exposed sections 16 are inserted into a gap of the pressing plate 13A, and the exposed sections 16 and the pressing plate 13A are welded by a high energy beam from a transverse direction through the slit 15. This provides a prismatic battery for large current application in electric vehicles and hybrid electric vehicles.